I am adding a phone number to my business account to send messages. I have added a phone number via WhatsApp Manager. After adding the phone number I have verified via SMS. However the status of the phone number is pending and requires the downloading of the certificate. However the documentation relation to the downloading of the certificate is to do with On-Premises API which has been sunsetted. Just to add that the business has been verified and the display name for the phone number has also been verified. How to I verify the phone number in order to send messages.