I want to run function or database queries after user signs up with github oauth?

import NextAuth from "next-auth/next";
import CredentialsProvider from "next-auth/providers/credentials";
import GitHubProvider from "next-auth/providers/github";
import { PrismaAdapter } from "@auth/prisma-adapter";
import { PrismaClient } from "@prisma/client";

const prisma = new PrismaClient();

export const handler = NextAuth({
  adapter: PrismaAdapter(prisma),
  pages: {
    signIn: "/auth/login",
  },
  session: {
    strategy: "jwt",
  },
  providers: [
    GitHubProvider({
      clientId: process.env.GITHUB_CLIENT_ID ?? "",
      clientSecret: process.env.GITHUB_CLIENT_SECRET ?? "",
      allowDangerousEmailAccountLinking: true,
    }),
    CredentialsProvider({
      // The name to display on the sign in form (e.g. 'Sign in with...')
      name: "Credentials",
      // The credentials is used to generate a suitable form on the sign in page.
      // You can specify whatever fields you are expecting to be submitted.
      // e.g. domain, username, password, 2FA token, etc.
      // You can pass any HTML attribute to the <input> tag through the object.

      credentials: {
        name: {},
        email: {},
        password: {},
      },
      async authorize(credentials, req) {
        const res = await fetch(
          `${process.env.NEXT_PUBLIC_WEBSITE_URL}/api/auth/login`,
          {
            method: "POST",
            body: JSON.stringify(credentials),
            headers: { "Content-Type": "application/json" },
          }
        );
        const user = await res.json();

        // If no error and we have user data, return it
        if (res.ok && user) {
          console.log(user);
          return user;
        }
        // Return null if user data could not be retrieved
        return null;
      },
    }),
  ],
});

export { handler as GET, handler as POST };