Login by social networks without Passport - what algorithm?

Question

Node.js

I set the task to make a social login with Facebook/Google/Twitter without PassportJS.
Before that, I made local and JWT.
Where to start, what principle, algorithm?
I so understood it is necessary to watch OAuth 2.0? Or can I apply JWT here?
What auxiliary libs are needed (NOT Passport)?

Answer 1

https://developers.facebook.com/docs/facebook-login/web
https://developers.google.com/identity/sign-in/web/
https://dev.twitter.com/web/sign-in /implementation