v1alpha1 Issue When creating a gateway, permissions can take more than a minute to propagate through the system. Therefore, you might see a “missing tokens” error when making a request to an API. If you see this error, wait several minutes, then retry the request. Issue Authentication is only supported for Cloud Run and Cloud Functions, not for App Engine. Announcement Released the Alpha version of API Gateway. To provide feedback or to log issues with this release, see Getting support.