Log into Github, go to your account settings and click Register a New Application.
Fill in the application name (it can be anything, though your users will see it during the sign in flow). In Homepage URL, put your account’s authorization domain, found in the authorization domain section of the Cloudflare Access dashboard. It is likely https://something.cloudflareaccess.com. In Authorization callback URL, put your authorization domain followed by /cdn-cgi/access/callback. Click Register Application.
Copy your OAuth ID and secret and paste them in the Cloudflare dashboard to finish connecting Github.
Click Done and then Click “Save and test” on the Cloudflare dashboard to make sure your connection to the identity provider is successful.