I'm trying to use webhooks to trigger builds with apps in OCP4.

The trigger URL generated by OpenShift is:
https://api.ocp.stg.fedoraproject.org:6443/apis/build.openshift.io/v1/namespaces/noggin/buildconfigs/noggin/webhooks/<secret>/github

When I put that in Github (with the proper secret obviously), webhooks fail with the error:
We couldn’t deliver this payload: x509: certificate signed by unknown authority

If I remove the port number to use the default port, which is what I did with openshift 3, I now get:
We couldn’t deliver this payload: x509: certificate is valid for *.stg.fedoraproject.org, stg.fedoraproject.org, not api.ocp.stg.fedoraproject.org

This worked with openshift 3 because the hostname was just "os.fedoraproject.org", no subdomain. So I tried removing the api. subdomain and got a 503 from Openshift with:
Application is not available

I could disable the SSL check in Github, but it's not recommended, and I can't do that in Pagure.