To register WhatsApp Business API, you can use your current WhatsApp or WhatsApp Business number, but you have to delete the previous account that has been registered.
It is highly recommended to register WhatsApp Business API with a number that has never been registered for WhatsApp or WhatsApp Business.
You can delete your WABA number if the business has sent paid messages within the last 30 days using that number. Once a number has been deleted from the WhatsApp Business Platform, it can be used again in the WhatsApp app, or may be registered again in the WhatsApp Business Platform. Note that different rules apply to deleted phones that had been banned by the WhatsApp Business Platform. Learn more
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If you want to use WhatsApp and WhatsApp Business, you must obtain a new phone number.
For more detailed information, you can refer to these link https://developers.facebook.com/docs/whatsapp/phone-numbers#manage-waba-phone-numbers