It is your number, and your WhatsApp Business account
Vatdi does not give you a number and does not resell messaging. You connect the WhatsApp Business account your business already owns, and it stays in your name: your display name, your verification, your billing relationship with Meta. Vatdi is the software that reads the messages arriving on it and writes the replies.
That matters for two reasons. Your customers keep messaging the number printed on your packaging and your shopfront, so nothing has to be re-advertised. And if you ever stop using Vatdi, the number and the account go with you — there is nothing to port and no number to give up.