Unable to get UPI response on web

I am trying to integrate UPI payments in an app and website. Everything works fine when I form the url (an example below) and launch an Intent on Android.

upi://pay?pa=abc@xyz&pn=ABC I get the response in the calling Android app using onActivityResult but I am not sure how do we get the response if we launch the PSP app (Google Pay or BHIM) from a website on the phone.

neither am i able to open the upi app from phone on browser not am i able to get the result. i am new to this, so i have no idea how to do it. please guide with a proper example of either html or php.