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

async function handleRequest(request) {
  const url = new URL(request.url)
  url.hostname = 'SOME_HOSTNAME' // i.e. 'dev-w-47n-vy-cd-e88kLg26GFbLGgBI.edge.tenants.auth0.com'
  request = new Request(request)
  request.headers.set('cname-api-key', 'SOME_KEY') // i.e. 'd4f2f3ef5a3ee3af4846127281d3450628bdc16d63e802dea75878fe9a63a279'
  
  try {
    return await fetch(new Request(url, request))
  } catch (e) {
    return new Response(JSON.stringify({ error: e.message }), { status: 500 })
  }
}