[google-appengine] App Engine microservices + IAP + API Gateway

Hello, I'm using API Gateway for different App Engine microservices, I'm following the tutorial here but when I turn on the IAP for App Engine and I try to make a request through the Gateway, I get a redirection response. If I

[google-appengine] Re: Give IAP permission to App engine standard services

I think you got the correct idea. However I am not sure if the guide here about signed headers is useful. In terms of access control, the role "IAP-secured web app" user should be sufficient. I assume that your concern here is not about authorization