Output URL isn't compatabile with IAP

[Jipje]

TL;DR

The .outputs.url url seems to have the following structure: https://.<project_name>.ew.r.appspot.com/ When adding IAP (identity aware proxy) and using flag promote: false this URL errored with error code 52.

Detailed design

I am using this GitHub Action to deploy a branch to a staging environment meaning I use promote: false. This worked correctly however when I added IAP to my App Engine this started erroring.

Accessing the version directly through Google App Engine however gave me the following URL: https://-dot-<project_name>.ew.r.appspot.com/ which did seem to work.

Additional information

This is the step from my .yaml:

      - id: 'deploy'
        name: 'Deploy the current branch to google app engine with no traffic'
        uses: 'google-github-actions/deploy-appengine@v0'
        with:
          promote: false

I referenced the url by using: [this url](${{ steps.deploy.outputs.url }})