Go to developers.facebook.com and Create App.
Select Business Type as the app type and proceed.
Provide a name for your app (avoid using trademarked names such as “WhatsApp” or “Facebook”).
Once the app has been created, click the WhatsApp button on the next screen to add WhatsApp sending capabilities to your app.
On the next screen, you will be required to link your WhatsApp app to your Facebook business account. You will also have the option to create a new business account if you don’t have one yet.