How to use the passport-oauth2 function in passport-oauth2

const apiKey = req.header("X-Api-Key");
      if (!apiKey) return cb("API key missing");

      const userId = await apiLogins.getUserIdByApiKey(apiKey);
      if (userId) {
        return cb(null, { apiKey, userId });
      }

      cb("API key not found");
    }),
  );

  // Initialize OAuth2 for Discord login
  // When the user logs in through OAuth2, we create them a "login" (= api token) and update their user info in the DB
  passport.use(
    new OAuth2Strategy(
      {
        authorizationURL: "https://discordapp.com/api/oauth2/authorize",
        tokenURL: "https://discordapp.com/api/oauth2/token",
        clientID: process.env.CLIENT_ID,
        clientSecret: process.env.CLIENT_SECRET,
        callbackURL: process.env.OAUTH_CALLBACK_URL,
        scope: ["identify"],
      },
      async (accessToken, refreshToken, profile, cb) => {
        const user = await simpleDiscordAPIRequest(accessToken, "users/@me");

        // Make sure the user is able to access at least 1 guild
        const permissions = await apiPermissionAssignments.getByUserId(user.id);
        if (permissions.length === 0) {
          cb(null, {});
          return;

module.exports = function (server, config) {
  const oauth2Strategy = new OAuth2Strategy(
    {
      scope: 'profile email openid',
      authorizationURL: config.get('AUTH_OAUTH2_AUTHORIZATION_URL'),
      tokenURL: config.get('AUTH_OAUTH2_TOKEN_URL'),
      clientID: config.get('AUTH_OAUTH2_CLIENT_ID'),
      clientSecret: config.get('AUTH_OAUTH2_CLIENT_SECRET'),
      callbackURL: config.get('AUTH_OAUTH2_CALLBACK_URL'),
    },
    (accessToken, refreshToken, params, profile, cb) => {
      const err = null;
      const user = getOauth2User(accessToken, params, profile);
      const info = accessToken;
      return cb(err, user, info);
    },
  );

import request from 'request';
import passport from 'passport';
import OAuth2Strategy from 'passport-oauth2';

import { authenticateOrLogin } from './middleware';

const {
  GRAVITY_API_URL,
  GRAVITY_ID,
  GRAVITY_SECRET,
} = process.env;

const strategy = new OAuth2Strategy({
  authorizationURL: GRAVITY_API_URL + '/oauth2/authorize',
  tokenURL: GRAVITY_API_URL + '/oauth2/access_token',
  clientID: GRAVITY_ID,
  clientSecret: GRAVITY_SECRET,
  callbackURL: '/auth/artsy/callback',
}, (accessToken, refreshToken, profile, done) => {
  request({
    url: GRAVITY_API_URL + '/api/v1/me',
    headers: { 'X-Access-Token': accessToken },
  }, (err, res, body) => {
    done(null, JSON.parse(body));
  });
});

passport.use('artsy', strategy);
passport.serializeUser((user, done) => done(null, user));