Can't get JWT for user

[Azer0s]

Checklist

• The issue can be reproduced in the nextjs-auth0 sample app (or N/A).
• I have looked into the Readme, Examples, and FAQ and have not found a suitable solution or answer.
• I have looked into the API documentation and have not found a suitable solution or answer.
• I have searched the issues and have not found a suitable solution or answer.
• I have searched the Auth0 Community forums and have not found a suitable solution or answer.
• I agree to the terms within the Auth0 Code of Conduct.

Description

I am currently trying to get the JWT for a user to later use against a Java Spring backend but unfortunately, nothing has worked so far.

export default async function RootLayout({
  children,
}: Readonly<{ children: React.ReactNode }>) {
  let session: SessionData | null = null;
  try {
    session = await auth0.getSession();

    const { token } = await getAccessToken();
    console.log(token);
  } catch (err) {
    void err;
  }
...

This always causes the following error:

[TypeError: Failed to parse URL from /auth/access-token] {
  [cause]: [TypeError: Invalid URL] {
    code: 'ERR_INVALID_URL',
    input: '/auth/access-token'
  }
}

When I tried manually getting the token via fetch like so

export default async function RootLayout({
  children,
}: Readonly<{ children: React.ReactNode }>) {
  let session: SessionData | null = null;
  try {
    session = await auth0.getSession();

    const host = (await headers()).get("host");

    const tokenRes = await fetch(`http://${host}/auth/access-token`).then(
      (res) => res.json()
    );
    console.log(tokenRes);
  } catch (err) {
    void err;
  }
...

I get another error message telling me that the user does not have an active session.

{
  error: {
    message: 'The user does not have an active session.',
    code: 'missing_session'
  }
}

Reproduction

As seen above

Additional context

I can get the session with await auth0.getSession() but when I try to access the token, I get a JWE instead of a JWT. The AUTH0_AUDIENCE is set in my .env.local file.

nextjs-auth0 version

^4.0.3

Next.js version

15.2.1

Node.js version

23.6.0