Log in to your company's Facebook Business Manager account.

• Go to Business settings.
• Under Business Manager info, you will see your Business Manager ID number.
• Go to your Sparrow dashboard, copy this number into the Your Facebook ID section and press Save.
• And that's it! Make sure all your information is correct and press Submit request.

The Business Manager ID is used for WhatsApp to confirm your brand's/company's identity on Facebook (since Facebook owns WhatsApp), because the WhatsApp API is on Facebook, and also so that Facebook can approve your sender names: it must confirm this through your official account.