const initialize = async app => {
    server = http.createServer(app);

    app.use(bodyParser.urlencoded({extended: true}));
    app.use(helmet());

    initSupertokens();

    app.use(
        cors({
            origin: function (origin, callback) {
                if (config.get("cors.whitelist").indexOf(origin) !== -1 || config.get("cors.allowLocal")) {
                    // error - null, allowOrigin - true
                    callback(null, true);
                } else {
                    app.use(function (err, req, res) {
                        res.status(403).json({
                            success: false,
                            statusCode: "NOT_ALLOWED_BY_CORS",
                            message: "You are not allowed to access this resource",
                            data: {},
                        });
                    });
                    // error - true, allowOrigin - false
                    callback(true, false);
                }
            },
            allowedHeaders: ["content-type", ...supertokens.getAllCORSHeaders()],
            credentials: true,
        })
    );

    app.use(middleware());

    app.get("/health", (req, res) => {
        res.status(200).send({PBL: "Up and Running"});
    });
    
    app.use(errorHandler());

    app.enable("trust proxy");

    server.listen(config.api.port);
    server.timeout = config.get("server.timeout");
    logger.info(`Server started at port ${config.api.port}`);
};

And this init function is called at the start of the App