Scan to pay option using tera wallet balance

Hi there, I have built a multivendor site and the vendors use tera wallet for purchasing and receiving payments. I will like to attach a UPI setting where local stores in my country can scan a QR code from the sellers screen and pay from tera wallet balance. This must be accessible via a scan to pay pay in the website. Need Html code to place in page to scan qr code and debit funds from user tera wallet balance.

Also the seller would have a separate page to generate the QR code after they simply enter a price and order description. Need code to place on an Html page to access tera wallet to perform the request above.