The subscriber will be able to subscribe to the hub, then later you can check whether the subscriber is subscribed to a specific hub.
It is important to understand that the tool is intended primarily for subscribing to mailing lists, but due to the lack of an official interface for mailing lists on our part, and a high risk of ban from WhatsApp, you must implement mailings on your side using our API, sending messages strictly in case of urgent need. These can be notifications about debiting funds, mass information, sending order status, etc.