ERR_NGROK_SHIP_POOL_KIND_SCALE_UNSUPPORTED: Compute pools of kind KIND have no node counts to change - ngrok documentation

What does ERR_NGROK_SHIP_POOL_KIND_SCALE_UNSUPPORTED mean?

ngrok returns ERR_NGROK_SHIP_POOL_KIND_SCALE_UNSUPPORTED with this message:

Compute pools of kind <KIND> have no node counts to change.

Where can I get more help with ERR_NGROK_SHIP_POOL_KIND_SCALE_UNSUPPORTED?

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