from Github is done in your account profile settings under 'developer settings', then 'OAuth applications'. Click 'Register a new application', name your app, paste in the url to your glitch homepage (Not the project code's url), and lastly for the callback url, paste in the same url as the homepage but with '/auth/github/callback' added on. This is where users will be redirected to for us to handle after authenticating on Github. Save the returned information as 'GITHUB_CLIENT_ID' and 'GITHUB_CLIENT_SECRET' in your .env file.
On your remixed project, create 2 routes accepting GET requests: /auth/github and /auth/github/callback. The first should only call passport to authenticate 'github' and the second should call passport to authenticate 'github' with a failure redirect to '/' and then if that is successful redirect to '/profile' (similar to our last project).
An example of how '/auth/github/callback' should look is similar to how we handled a normal login in our last project: app.route('/login')
.post(passport.authenticate('local', { failureRedirect: '/' }), (req,res) => {
res.redirect('/profile');
});
Submit your page when you think you've got it right. If you're running into errors, you can check out the project up to this point here.