How to check if the client's phone is connected to WhatsApp?
You can find out if the client number is connected to Whatsapp in several ways
1 - Use the CheckPhone method:
2 - or by the UserStatus method:
At the same time, please note that if the user hides information about their status, you will not be able to use this method to check it. Moreover, if you yourself have hidden information about your status in the privacy settings of your WhatsApp profile, you will also not be able to request the status of other users.
Also, if the client number is not in Whatsapp, then Hooks for the "Delivered" and "Read" status will not be generated.