GitHub doesn't support the OAuth Implicit flow so you need some server code to handle Authorization flow so I thought I would use Netlify Functions for it.

Largely based on: intercom-netlify-oauth.

• gatekeeper
• micro-github

Create an OAuth App

Setup a Netlify project and configure the the following environment variables; CLIENT_SECRET and REACT_APP_CLIENT_ID.

Netlify Dev.

npm install -f netlify-cli
netlify login
netlify link

netlify dev

Netlify Dev is pretty cool, it can run your server function locally.