WhatsApp Web doesn't generate a QR code when opened on Android phone's browsers.
I have already changed my settings to the desktop view, but still, the QR code is not generated.
How to show WhatsApp Web's QR code on Android phone's browsers?
If you're using Google Chrome for Android, then go to the menu, find the Desktop Site option, and see if it is already checked or not.
If not, then tap on it. It will be checked & show you the Desktop Version where you'll see the QR Code.
As far as I know, you can't open WhatsApp Web on a phone as of now.
I have also tried many times before using many different browsers, but no go. Maybe in a later time, some new browser or setting can enable this.