NEXTJS_NO_FETCH_IN_SERVER_PROPS

Conformance is available on Enterprise plans

Since both getServerSideProps and API routes run on the server, calling fetch on a non-relative URL will trigger an additional network request.

Instead of using fetch to make a call to the API route, you can instead share the code in a shared library or module to avoid another network request. You can then import this hared logic and call directly within your getServerSideProps function, avoiding additional network requests entirely.