ERR_NGROK_SHIP_PUBLISH_TARGET_APP_CONFLICT: Publish target ID is used by COUNT apps: NAMES - ngrok documentation

What does ERR_NGROK_SHIP_PUBLISH_TARGET_APP_CONFLICT mean?

ngrok returns ERR_NGROK_SHIP_PUBLISH_TARGET_APP_CONFLICT with this message:

Publish target <ID> is used by <COUNT> apps: <NAMES>. Point them at another target first.

Where can I get more help with ERR_NGROK_SHIP_PUBLISH_TARGET_APP_CONFLICT?

Email support@ngrok.com and include the error code.