Status 400 for method post using workers with code attached

Developers Workers
1

What is wrong with this code that if you use with any wordpress sites, it will return status 400 for anything that has:

/wp-admin/admin-ajax.php

method POST with xhr

How do I resolve this?

addEventListener('fetch', event => {
  event.respondWith(handleRequest(event.request))
})

async function handleRequest(request) {
  response = await fetch(request.url)
  return new Response(response.body,response)
}