I want to set maxAge to the value that BE gives me. BE gives me back: “expires”: “2024-07-23T22:12:36.505Z” and I want that NextAuth session to be equal to this value for example. How to achieve that?

I don’t want to set maxAge to a static value, because maxAge of the session can change from time to time and BE gives that in the format: “expires”: “2024-07-23T22:12:36.505Z”

import NextAuth, { Session } from 'next-auth';
import CredentialsProvider from 'next-auth/providers/credentials';
import { JWT } from 'next-auth/jwt';
import { cookies } from 'next/headers';

let backendsSessionMaxAge: number;
let backendSessionName: string;

const authOptions = {
  providers: [
    CredentialsProvider({
      name: 'Credentials',
      credentials: {
        email: { type: 'email' },
      },
      async authorize(credentials, req) {
        try {
          const response = await fetch(
            `${ENV_VARIABLE}/login`,
            {
              method: 'POST',
            }
          );
          if (response.ok) {
            const user = await response.json();
            const setCookieHeader = response.headers.get('set-cookie');
            if (setCookieHeader) {
              backendSessionName = setCookieHeader.split('=')[0];
              const backendSessionValue = setCookieHeader
                .split(';')[0]
                .split('=')[1];
              const maxAgeRegex = /Max-Age=(d+)/;
              const match = setCookieHeader.match(maxAgeRegex);
              backendSessionMaxAge= match ? Number(match[1]) : 0;
              cookies().set({
                name: backendSessionName,
                value: backendSessionValue,
                httpOnly: true,
                sameSite: 'lax',
                path: '/',
                maxAge: backendSessionMaxAge,
              });
            }
            return user;
          } else {
            console.error('Invalid email:', response.status);
          }
        } catch (error) {
          console.error('Login Service not available: ', error);
        }
      },
    }),
  ],
  callbacks: {
    async jwt({
      token,
      user,
      trigger,
      session,
    }: {
      token: JWT;
      user: Session['user'];
      trigger?: JWT['trigger'];
      session?: Session;
    }) {
      if (user) {
        token.user = user;
      }
      if (trigger === 'update' && session) {
        token = { ...token, user: session };
      }
      return token;
    },
    async session({ session, token }: { session: Session; token: JWT }) {
      if (token.user) {
        session.user = token.user;
      }
      // Dynamically set the session expires
      if (backendSessionMaxAge) {
        const expirationDate = new Date(
          Date.now() + backendSessionMaxAge * 1000
        ).toISOString();
        session.expires = expirationDate;
      }
      return session;
    },
    async redirect({ url, baseUrl }: { url: string; baseUrl: string }) {
      if (url.startsWith('/')) return `${baseUrl}${url}`;
      else if (new URL(url).origin === baseUrl) return url;
      return baseUrl;
    },
  },
  events: {
    async signOut() {
      cookies().set('backend-session ', '', { httpOnly: true, sameSite: 'lax' });
      // empty custom cookie value
    },
  },
session: {
maxAge: 50, //50 seconds
// || backendSessionMaxAge didnt get it work

},

  pages: { signIn: '/login' },
};

const handler = NextAuth(authOptions);

export { handler as GET, handler as POST };