This is for the momo collection for Kenya, Rwanda, Uganda and Ghana. The OTP object in the payload is an optional field, it's only needed when your business account isn't whitelisted for verifying phone numbers before collections, using the collection OTP endpoint. If you have a system in place to verify phone numbers in your app then reach out to us to whitelist your account so you can proceed to integrate this collection API without the need for a phone number verification endpoint(OTP collection)