Zero-Fee UPI Payment Integration for reactjs website needed

I have a ReactJS storefront that already works end-to-end with Razorpay, however the 2 % MDR is unacceptable for my margins. I need the entire flow replaced with a truly zero-fee UPI solution and kept production-ready within one week... (Budget: ₹37500 - ₹75000 INR, Jobs: AngularJS, API Integration, Frontend Development, HTML, HTML5, JavaScript, Node.js, Payment Gateway Integration, React.js, Web Development)