try deploying it and see if it still throws an error

function myFetch(input: RequestInfo, init?: RequestInit<CfProperties<unknown>> | undefined): Promise<Response> {
  console.log("myFetch", input, init);
  return fetch(input, init);
}

function myFetch(input: RequestInfo, init?: RequestInit<CfProperties<unknown>> | undefined): Promise<Response> {
  console.log("myFetch", input, init);
  return fetch(input, init);
}