Online merchants which have QR code vs UPI ID

So I would like (with the help of fellow dimers) to make a list of online merchants/websites/apps which accept payment via

QR code

vs

UPI ID

e.g. IRCTC website shows QR code to pay. When I bought medicines from MediBuddy, it used RazorPay gateway which also had QR code option. Amazon has Pay on Delivery option (not just cash) where we can ask delivery person to show QR code to scan and pay or generate link to pay.

But most online sites have VPA/UPI ID only e.g. Flipkart, 1mg, BigBasket.

So which other merchants you know have scan QR option?

It is because of credit card rewards that I need to know this. Certain offers from RuPay e.g. Scan and Score or Paytm offers or Kiwi app are on scan and pay QR txns while some are on online UPI ID txns.