Currently, manual host action which has type of webhook(only type allowing use of js via  gui) , is only run on zabbix-server eventhough host in hostgroup that has this action defined is monitored via zabbix-proxy. It would be good to allow that type to be run on zabbix-proxy too, since not everyone wants to open connections from server to "everywhere" and there wouldn't be need of manual maintenance of external-scripts between different zabbix-proxies.