ERR_NGROK_SHIP_POOL_NODE_POOL_FIELD_REQUIRED: The 'node_pools[INDEX].FIELD field must not be empty - ngrok documentation

What does ERR_NGROK_SHIP_POOL_NODE_POOL_FIELD_REQUIRED mean?

ngrok returns ERR_NGROK_SHIP_POOL_NODE_POOL_FIELD_REQUIRED with this message:

The 'node_pools[<INDEX>].<FIELD> field must not be empty.

Where can I get more help with ERR_NGROK_SHIP_POOL_NODE_POOL_FIELD_REQUIRED?

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