I have a Swagger/OpenAPI API running on Google App Engine behind Google's Identity Aware Proxy. I can hit the URLs directly, which causes a normal authentication flow and authenticates me using my Google account.
I create an External Service with the "Service Schema Relative URL" of "/v1/openapi.json" and receive "An error was encountered while trying to retrieve the service schema."
The full URL is valid, adding the path to the URL defined in the Named Credential.
Pasting the contents of the json into the "Service Schema Complete JSON" field gets me to the next screen, but no actions get defined.
Any ideas what could be wrong? The json is a Swagger/OpenAPI definition that appears to validate for me.