ERR_NGROK_SHIP_RUNNER_DECOMMISSION_NOT_ALLOWED: Runner ID runs the whole compute pool, so it cannot be removed on its own - ngrok documentation

What does ERR_NGROK_SHIP_RUNNER_DECOMMISSION_NOT_ALLOWED mean?

ngrok returns ERR_NGROK_SHIP_RUNNER_DECOMMISSION_NOT_ALLOWED with this message:

Runner <ID> runs the whole compute pool, so it cannot be removed on its own. Delete the pool to remove it.

Where can I get more help with ERR_NGROK_SHIP_RUNNER_DECOMMISSION_NOT_ALLOWED?

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