What is the best way to forward the client stored cookie to the server action.

The client browser has an auth_token cookie stored with the session token for the user. The user will navigate to a page that will make a request that requires authentication e.g. /private-user-stuff. The call is made to /api/some-authenticated-endpoint the page component, so this request is running on the server. The api is then taking the auth_token cookie from the request and parsing it and doing its checks.

How can I get that client auth_token cookie onto the request that is being sent from the server so that my api is able to authenticate that session token?

Basic example of current setup, just simple NextJs page with a fetch call:

// Page which will get some data that requires authenticated user

export async function doStuffWithApi() {
  // the backend is going to be checking for a cookie called auth_token on the request
  // because this request is being run server-side that cookie doesn't exist
  // somehow I need to forward the client cookie to this server request so that it can be authenticated by my backend
  const response = await fetch('/api/user-photos');
  return response.json();
}

export default async function Page() {
  const result = await doStuffWithApi();

  return <div>{result}</div>
}