I've got a Google Apps Script attached to a Google Sheet that is triggered when a new entry comes in. I've also got a Google Cloud Run instance for a Flask app that I access through an end-point.
Currently it allows unauthenticated invocations but I want to only allow authenticated invocations. How do I go about doing this? I can't access the metadata server as its outside of GCP and the Calling From Outside GCP suggests following the Identity-Aware Proxy sample code however IAP does not work for Cloud Run...
Is there any simple way of doing this?