I have written the code for checking whether an user exists or not . On the basis of that, we are redirecting using res.redirect .

app.post('/UserRegister', async (req, res, next) => {
    const { username, password } = req.body;
    const isTheir = await User.exists({ username: username});
    console.log(isTheir);
    if (isTheir==true) {
        return next(new AppError("User Already Registered", 501));
    }
    const user = new User({username});
    const registeredUser = await User.register(user, password);
    console.log("Going to Search Flights");
    res.redirect('/searchFlights');    
});

It seems that the res.redirect is not working since it's not going to searchFlights . Please help .