Can’t see device serial numbers in Apple ID settings

I need to get the serial numbers for some devices I do not physically have anymore (whether device itself or box or invoice).

Official Apple documentation says to go to appleid.apple.com and click on the device(s) you’d like, or simply locally on a device in Settings.app —> Apple ID —> select a device. All of these give some information, but not serial number. Every other website says it should appear right above the IMEI but it does not. I do not have 2 factor authentication enabled.

What's going on?

Picture upload is currently broken so the screenshot is at https://imgur.com/a/JgwmLrx