Grafana 9 Alerts - WebEx Contact Point (open source)

Trying to configure a WebEx contact point to send alerts to. Have successfully created a WebEx space, retrieved Room Id, Created Bot, Created a Contact Point with Bot Token and Room Id.
Verified in WebEx can send with Bot to Room, but Grafana’s Post to fails with EOF. Tried test message, tried hardcoded Notification template. Need ideas for what to try next.