This process just takes a few simple steps, do this so that messages get to your agents:

1 - Go to business.facebook.com then select your business and the corresponding ad account.

2 - In the Campaigns tab, click Create:

3 - Select the campaign objective Traffic: 

4 - You'll see the settings options below. Click Continue:

5 - In the Traffic section select WhatsApp and your page. You will need to be a page administrator to continue:
6 - To complete the process, add the phone number you use with Zenvia Conversion, including the area code. For Buenos Aires, Argentine, it would be 9-11-xxxxxxxx.
7 - You'll receive a code at that WhatsApp number that you'll need to enter in the following screen:
8 - Click Send and you're all set! Your WhatsApp number is now integrated with Facebook.