How should i process a payment in android app?

Question

I will use any payment gateway like Razorpay, Payumoney, Paytm.

My question is how should I process it. I mean should I upload the item details first in the database then according to what happens at the payment gateway I will update the status of the item in the database.

Answer 1

Refer to the the documentation of payment gateway you are using

Answer 2

Is item uploading part done by gateways ?

Answer 3

No item uploading isn't done by gateways.
You have to pass order id and amount to payment gateways.(Some payment gateways provide coupon system, IDK how it works).

And about items in cart, you have to self manage them and add in users order history after a successful payment response