Strapi Next-Auth credentials provider

[...nextauth].js

import NextAuth from "next-auth";
import Providers from "next-auth/providers";

const options = {
  providers: [
    Providers.Credentials({
      // 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.
      credentials: {
        email: { label: "Email", type: "text"},
        password: { label: "Password", type: "password" }
      },
      async authorize(credentials) {
        // You need to provide your own logic here that takes the credentials
        // submitted and returns either a object representing a user or value
        // that is false/null if the credentials are invalid.
        // e.g. return { id: 1, name: 'J Smith', email: 'jsmith@example.com' }
        var fetch_url = `${process.env.NEXT_PUBLIC_API_URL}/auth/local`;
        var params = {
          method: "POST",
          headers: {
            'Accept': 'application/json',
            'Content-Type': 'application/json'
          },
          body: JSON.stringify({
            identifier: credentials.email,
            password: credentials.password
          })
        }

        let response = await fetch(fetch_url, params);
        const data = await response.json();
        const user = { ...data.user, jwt: data.jwt }

        if (user) {
          return user
        } else {
          return null
        }
      }
    })
  ],
  database: process.env.NEXT_PUBLIC_DATABASE_URL,
  session: {
    jwt: true,
  },
  callbacks: {
    session: async (session, user) => {
      session.jwt = user.jwt;
      session.id = user.id;
      return Promise.resolve(session);
    },
    jwt: async (token, user, account) => {
      const isSignIn = user ? true : false;
      if (isSignIn) {
        if (account.type == 'credentials') {
          token.jwt = user.jwt;
          token.id = user.id;
        } else {
          var fetch_url = `${process.env.NEXT_PUBLIC_API_URL}/auth/${account.provider}/callback?access_token=${account?.accessToken}`;
          let response = await fetch(fetch_url, params);
          const data = await response.json();
          token.jwt = data.jwt;
          token.id = data.user.id;
        }
      }
      return Promise.resolve(token);
    },
  },
};

const Auth = (req, res) =>
  NextAuth(req, res, options);

export default Auth;