Hi there,
Well today i was learning next-auth but i'm confused wheather how can i save user or should i save user on database for dynamic rendering with unique user data??

So, for my app needs users to have different data which will be saving on mongodb so for that i need user's id or some of primary key ( PK ) how can i do that??

import NextAuth from "next-auth";
import GithubProvider from "next-auth/providers/github";

const handler = NextAuth({
  providers: [
    GithubProvider({
      clientId: process.env.GITHUB_ID!,
      clientSecret: process.env.GITHUB_SECRET!,
    }),
  ],
});

export { handler as GET, handler as POST };

This above code is simple but doesn't accept any callbacks, i dont know why callbacks are required although i wanan learn but i dont have any ressources docs are outdated as everyone says!!

Thanks for your time.