Hi Ladi,
You needs to use any one of payment gate way to achieve the payment
https://marketplace.mendix.com/link/component/203738
https://marketplace.mendix.com/link/component/207076
https://marketplace.mendix.com/link/component/119366
Create a microflow in Mendix that will handle the payment processing logic.
Create a page with payment options like UPI, credit card, and debit card.
On the "Order Now" button click, navigate to the payment options page