Turning off find my iPhone when your screen is broken

My son has broke the screen on his iPhone se 2nd gen. In order to get a new phone I have to turn off find my iPhone on his current one. Well with the screen broken it is literally impossible to do this. This is a problem Apple needs to fix. It is literally ridiculous. Before I get told that I can do this online, no you can’t. Because Apple sends the tfa or two factor authentication code to that phone, which with the screen cracked is impossible. So you also can’t delete that said phone from iCloud.com without entering the tfa. Last time his screen messed up and wasn’t broken, we had to drive to the Apple store which isn’t close to our house, bring the original purchase receipt to get Apple to turn off find my iPhone. I love my iPhone but having to deal with this twice within a couple months has literally been a pain. The first time it was a hardware issue which caused the screen to go black. Also we can’t sign into his Apple ID on another iPhone because it wants us to confirm it on the broke phone.