allow crossorigin in express js

https://www.fullstacktutorials.com/interviews/top-10-express-js-interview-questions-answers-30.html

    app.use((req, res, next) => {

        res.setHeader("Access-Control-Allow-Origin", "*");

        res.setHeader("Access-Control-Allow-Headers", "Content-Type, X-Requested-With, OPTIONS, Origin,auth-token");

        res.setHeader("Access-Control-Allow-Methods", "GET, POST, PUT, PATCH, DELETE");

        next();

    });