passport.use(  //The
     new GoogleStrategy({
     callbackURL: '/auth/google/redirect', 
     clientID: keys.google.clientID,
     clientSecret: keys.google.clientSecret
       //options for strategy to configure
      },  (accessToken, refreshToken, profile, done) => {
       //check if user already exist etc 

    })

        ////On the routes file 
          router.get('/google/redirect',passport.authenticate('google'),  (req, res) => { //Middleware forces authorisation from passport before allowed into the profile. 

       res.redirect("/profile/")