title: Permissions Denied on getSignedUrl Promise in Cloud Function
body: <p>I have an http onCall cloud function which I want to return a signedURL to allow me to upload a file to a cloud storage bucket <a href="https://stackoverflow.com/questions/62817559/cant-resolve-getsignedurl-promise-in-cloud-function/62818690#62818690">Previous question</a></p>
  <p>It keeps telling me permission is denied, but I can't see where the problem could be. The function GCPSecureURL is set to Allow unauthenticated, and StorageAdmin is set to all users.</p>
  <p>A service account also has access to StorageAdmin on the bucket, because a pub/sub subscribes to the event when a file is uploaded to the bucket and triggers a pdf conversion service.</p>
  <p>Why can't I get the signedURL back from the function?</p>
  <p>Right now the promise is pending, then the console logs a POST 500 error. The logs for the function say Unhandled error { Error: The caller does not have permission&quot; ...</p>