ERR_NGROK_SHIP_BUILD_CONFIG_RUN_COMMAND_TOO_LONG: The 'build_config.run_command' field is too long - ngrok documentation

What does ERR_NGROK_SHIP_BUILD_CONFIG_RUN_COMMAND_TOO_LONG mean?

ngrok returns ERR_NGROK_SHIP_BUILD_CONFIG_RUN_COMMAND_TOO_LONG with this message:

The 'build_config.run_command' field is too long. Max 4096 bytes, got <LENGTH> bytes.

Where can I get more help with ERR_NGROK_SHIP_BUILD_CONFIG_RUN_COMMAND_TOO_LONG?

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