About linking WhatsApp Business with Facebook and Instagram
You can link your WhatsApp Business account with a Facebook Page and/or Instagram Profile to give your customers an additional way to communicate with your business. When you link your Facebook Page or Instagram Profile with your WhatsApp Business account, your number will show up as a contact option on the linked Facebook Page and/or Instagram Profile. When a customer taps on this contact option, they’ll be able to message you directly on WhatsApp.
Once you’ve linked a Facebook Page to your WhatsApp Business account, you can sync business information from that Facebook Page to your WhatsApp Business account. This will automatically update your WhatsApp Business profile with information from the Facebook Page.