I see how to set up Back Tap but none of the options seem to function as a "back" button. Which option did you set it to?
I had the same issue - it eventually started working after restarting the phone.
Hmm did you set Double Tap to "Accessibility Shortcut"?
Oh, that's cool, but that's iPhone 12 only, right? Not iPhone 11?
It was added in iOS 14. Not hardware specific. It works on my iPhone 11 Pro Max. It's an accessibility feature that has to be specifically turned on though.
How do you actually make it go 'back' though? I only have options like "home" etc.. ?
It uses the accelerometer that has already been built in to iPhones going way way back (actually ALL iPhones have at least a 3-axis accelerometer), so that's why there is so much support for older devices.