hello there.
As you can see in our profile, we are a team of Android developers. The steps of your project are as follows:
1. Designing a page to add payment gateways
2. Modify pages in your app to add ways to transfer to the payment gateway
3. Connect the payment gateway to your application.
Note: At the end of each step, we will show you the result and if approved, we will go to the next step. Also, whenever you are not satisfied to continue working with us due to our mistake, we will be responsible for your losses.
Thanks & Regards
Joe B.