Can I use my phone number to work with WhatsApp via the Chat API?
Yes, you can use any number.
At the same time, if there is a mass mailing of messages from the number, this may lead to a ban from WhatsApp. Before connecting an instance, we recommend that you read our recommendations for working with the service – recommendations.
If you do not want to take risks, then you can start working with a new SIM card. Before that, you should spend at least a week with the number in the usual format of using it in WhatsApp. Call, write messages, add contacts, subscribe to groups.
New WhatsApp numbers have a lower "trust rating" and are more often banned in case of suspicious activity.
You can always test the new number and the operation of the service itself through the Chat API itself, using the "Testing" tool.