In app payment using Phone number. Like using USSD

Hi, everyone.
I’m from Tanzania
I’m very enjoying using Kodular as the way of creating App’s
I have created three apps and publish them in the play store, that was a long journey but it was helpful when I face some challenges in my project and try to find answers and the good is that many answers are there.
For now, I have created another project, the project will involve payment. I have searched the ways in which I can put payment to App, I got many ways but none of them work in my region.

Please I need your help, especially to integrate payment using this website which works in my country Pay, shop and receive payments - Tanzania | Pesapal and will be better if its payment through USSD form in which the customer required to put their pin for payment to be processed.

Can you not use in app billing?

Thanks for your replay, but can this In-app billing be possible for USSD payment. I’m asking this because in my app users most of them know to pay using USSD sim payment and not something like MasterCard or banking payment.

I have found this information from hover Get Paid In-App with Mobile Money | by David Kutalek | Hover | Medium and the same as I want to use but its implemented to Android studio and not kodular. can you help me to do the same in kodular because im codeless. that’s why I love modular.