How to use the altair-static.getDistDirectory function in altair-static

export const altairExpress = (opts: RenderOptions): express.Express => {
  const app = express();
  app.disable('strict routing');

  app.get('/', (req, res) => {
    if (req.originalUrl.substr(-1) !== '/') {
      // We need the trailing slash to enable relative file paths to work
      return res.redirect(301, req.originalUrl + '/');
    }
    return res.send(renderAltair(opts));
  });
  app.get('/initial_options.js', (req, res) => {
    res.set('Content-Type', 'text/javascript');
    return res.send(renderInitialOptions(opts));
  });
  app.use(express.static(getDistDirectory()));

  /**
   * Catch-all route
   */
  app.get('*', (req, res) => {
    return res.send('404.');
  });

  return app;
};

protocol.registerBufferProtocol('altair', (request, callback) => {

    const requestDirectory = getDistDirectory();
    const filePath = path.join(requestDirectory, new url.URL(request.url).pathname);
    const indexPath = path.join(requestDirectory, 'index.html');

    getFilePath(filePath).then((filePath) => {
      if (!filePath) {
        filePath = indexPath;
      }

      fs.readFile(filePath, 'utf8', function(err, data) {
        if (err) {
          return console.log('Error loading file to buffer.', err);
        }
        if (filePath && filePath.includes('index.html')) {
          data = renderAltair();
        }

router.get(`${url}/:path+`, async ctx => {
    await send(ctx, ctx.params.path, { root: getDistDirectory() });
  })
};