How to use the server.get function in server

AdyenHelper.savePaymentDetails(paymentInstrument, order, result);
            order.setPaymentStatus(dw.order.Order.PAYMENT_STATUS_PAID);
            order.setExportStatus(dw.order.Order.EXPORT_STATUS_READY);
            Transaction.commit();
            COHelpers.sendConfirmationEmail(order, req.locale.id);
            clearForms();
            res.redirect(URLUtils.url('Order-Confirm', 'ID', order.orderNo, 'token', order.orderToken).toString());
            return next();
        }
    }
    Logger.getLogger("Adyen").error("Session variable does not exists");
    res.redirect(URLUtils.url('Error-ErrorCode', 'err', 'general'));
    return next();
});

server.get('Adyen3DS2', server.middleware.https, function (req, res, next) {
    var protocol = req.https ? "https" : "http";
    var adyenGetOriginKey = require('*/cartridge/scripts/adyenGetOriginKey');

    try {
        var originKey = adyenGetOriginKey.getOriginKeyFromRequest(protocol, req.host);
        var environment = AdyenHelper.getAdyenMode().toLowerCase();
        var resultCode = req.querystring.resultCode;
        var token3ds2 = req.querystring.token3ds2;
        res.render('/threeds2/adyen3ds2', {
            locale: request.getLocale(),
            originKey: originKey,
            environment: environment,
            resultCode: resultCode,
            token3ds2: token3ds2
        });

AdyenHelper.savePaymentDetails(paymentInstrument, order, result);
        order.setPaymentStatus(dw.order.Order.PAYMENT_STATUS_PAID);
        order.setExportStatus(dw.order.Order.EXPORT_STATUS_READY);
        Transaction.commit();
        COHelpers.sendConfirmationEmail(order, req.locale.id);
        clearForms();
        res.redirect(URLUtils.url('Order-Confirm', 'ID', order.orderNo, 'token', order.orderToken).toString());
        return next();
    }

    Logger.getLogger("Adyen").error("Session variables for 3DS2 do not exists");
    res.redirect(URLUtils.url('Error-ErrorCode', 'err', 'general'));
    return next();
});

server.get('Redirect', server.middleware.https, function (req, res, next) {
    var signature = req.querystring.signature;
    var order = OrderMgr.getOrder(session.privacy.orderNo);
    if(order && signature){
        var paymentInstruments = order.getPaymentInstruments("Adyen");
        var adyenPaymentInstrument;
        var paymentData;

        //looping through all Adyen payment methods, however, this only can be one.
        var instrumentsIter = paymentInstruments.iterator();
        while (instrumentsIter.hasNext()) {
            adyenPaymentInstrument = instrumentsIter.next();
            paymentData = adyenPaymentInstrument.custom.adyenPaymentData;
        }
        var currentSignature = AdyenHelper.getAdyenHash(req.querystring.redirectUrl, paymentData);

        if(signature == currentSignature) {

/**
 * Inspect fields
 */
app.get('/:mapfile_64/fields.json', function(req, res) {
});

/**
 * Inspect data
 */
app.get('/:mapfile_64/data.json', function(req, res) {
});

/**
 * Inspect layer
 */
app.get('/:mapfile_64/:layer_64/layer.json', function(req, res) {
});

/**
 * Inspect field values
 */
app.get('/:mapfile_64/:layer_64/:feature_64/values.json', function(req, res) {
});

return next();
        }
    }
    else {
        Logger.getLogger("Adyen").error("No signature or no order with orderNo " + session.privacy.orderNo);
    }

    Logger.getLogger("Adyen").error("Redirect signature is not correct");
    Transaction.wrap(function () {
        OrderMgr.failOrder(order);
    });
    res.redirect(URLUtils.url('Checkout-Begin', 'stage', 'payment', 'paymentError', Resource.msg('error.payment.not.valid', 'checkout', null)));
    return next();
});

server.get('ShowConfirmation', server.middleware.https, function (req, res, next) {
    try {
        var order = OrderMgr.getOrder(session.privacy.orderNo);
        var paymentInstruments = order.getPaymentInstruments("Adyen");
        var adyenPaymentInstrument;
        var paymentData;

        //looping through all Adyen payment methods, however, this only can be one.
        var instrumentsIter = paymentInstruments.iterator();
        while (instrumentsIter.hasNext()) {
            adyenPaymentInstrument = instrumentsIter.next();
            paymentData = adyenPaymentInstrument.custom.adyenPaymentData;
        }

        //details is either redirectResult or payload
        var details;
        if (req.querystring.redirectResult) {

tl = require('tl');

app.get('/status.json', function(req, res) {
    res.send({ status: 'true' });
});

/**
 * Inspect fields
 */
app.get('/:mapfile_64/fields.json', function(req, res) {
});

/**
 * Inspect data
 */
app.get('/:mapfile_64/data.json', function(req, res) {
});

/**
 * Inspect layer
 */
app.get('/:mapfile_64/:layer_64/layer.json', function(req, res) {
});

/**
 * Inspect field values
 */
app.get('/:mapfile_64/:layer_64/:feature_64/values.json', function(req, res) {
});

'use strict';

var server = require('server');
var URLUtils = require('dw/web/URLUtils');
var Transaction = require('dw/system/Transaction');
var COHelpers = require('*/cartridge/scripts/checkout/checkoutHelpers');
var adyenHelpers = require('*/cartridge/scripts/checkout/adyenHelpers');
var OrderMgr = require('dw/order/OrderMgr');
var Resource = require('dw/web/Resource');
var Site = require('dw/system/Site');
var Logger = require('dw/system/Logger');
var AdyenHelper = require('*/cartridge/scripts/util/AdyenHelper');

const EXTERNAL_PLATFORM_VERSION = "SFRA";

server.get('Adyen3D', server.middleware.https, function (req, res, next) {
    var IssuerURL = req.querystring.IssuerURL;
    var PaRequest = req.querystring.PaRequest;
    var MD = req.querystring.MD;
    var TermURL = URLUtils.https('Adyen-AuthorizeWithForm');

    res.render('adyenform', {
        issuerUrl: IssuerURL,
        paRequest: PaRequest,
        md: MD,
        ContinueURL: TermURL
    });
    next();
});

server.post('AuthorizeWithForm', server.middleware.https, function (req, res, next) {
    var adyenCheckout = require('*/cartridge/scripts/adyenCheckout');

var app = require('server'),
    _ = require('underscore')._,
    tl = require('tl');

app.get('/:scheme/:mapfile_64/:z/:x/:y.*', function(req, res) {
    /*
     * scheme: (xyz|tms|tile (tms))
     *
     * format:
     * - Tile: (png|jpg)
     * - Data Tile: (geojson)
     * - Grid Tile: (*.grid.json)
     */
    try {
        var tile = new tl.Tile(
            req.params.scheme,
            req.params.mapfile_64,
            req.params.z,
            req.params.x,
            req.params.y,
            req.params[0]);

}
    catch (e){
        Logger.getLogger("Adyen").error("Could not verify /payment/details: " + e.message);
        res.redirect(URLUtils.url('Error-ErrorCode', 'err', 'general'));
        return next();
    }


});

server.get('OrderConfirm', server.middleware.https, function (req, res, next) {
    res.redirect(URLUtils.url('Order-Confirm', 'ID', req.querystring.ID, 'token', req.querystring.token).toString());
    return next();
});

server.get('GetPaymentMethods', server.middleware.https, function (req, res, next) {
    var BasketMgr = require('dw/order/BasketMgr');
    var Resource = require('dw/web/Resource');
    var getPaymentMethods = require('*/cartridge/scripts/adyenGetPaymentMethods');
    var Locale = require('dw/util/Locale');
    var countryCode = Locale.getLocale(req.locale.id).country;
    var currentBasket = BasketMgr.getCurrentBasket();
    if (currentBasket.getShipments().length > 0 && currentBasket.getShipments()[0].shippingAddress) {
        countryCode = currentBasket.getShipments()[0].shippingAddress.getCountryCode();
    }
    var paymentMethods;
    var descriptions = [];
    try {
        paymentMethods = getPaymentMethods.getMethods(BasketMgr.getCurrentBasket(), countryCode.value.toString()).paymentMethods;
        paymentMethods = paymentMethods.filter(function (method) {
            return !isMethodTypeBlocked(method.type);
        });

/**
 * Inspect data
 */
app.get('/:mapfile_64/data.json', function(req, res) {
});

/**
 * Inspect layer
 */
app.get('/:mapfile_64/:layer_64/layer.json', function(req, res) {
});

/**
 * Inspect field values
 */
app.get('/:mapfile_64/:layer_64/:feature_64/values.json', function(req, res) {
});

OrderMgr.failOrder(order, true);
            });
            res.redirect(URLUtils.url('Checkout-Begin', 'stage', 'placeOrder', 'paymentError', Resource.msg('error.technical', 'checkout', null)));
            return next();
        }
    }
    catch (e){
        Logger.getLogger("Adyen").error("Could not verify /payment/details: " + e.message);
        res.redirect(URLUtils.url('Error-ErrorCode', 'err', 'general'));
        return next();
    }


});

server.get('OrderConfirm', server.middleware.https, function (req, res, next) {
    res.redirect(URLUtils.url('Order-Confirm', 'ID', req.querystring.ID, 'token', req.querystring.token).toString());
    return next();
});

server.get('GetPaymentMethods', server.middleware.https, function (req, res, next) {
    var BasketMgr = require('dw/order/BasketMgr');
    var Resource = require('dw/web/Resource');
    var getPaymentMethods = require('*/cartridge/scripts/adyenGetPaymentMethods');
    var Locale = require('dw/util/Locale');
    var countryCode = Locale.getLocale(req.locale.id).country;
    var currentBasket = BasketMgr.getCurrentBasket();
    if (currentBasket.getShipments().length > 0 && currentBasket.getShipments()[0].shippingAddress) {
        countryCode = currentBasket.getShipments()[0].shippingAddress.getCountryCode();
    }
    var paymentMethods;
    var descriptions = [];