"Always on Display" and StandBy time limit settings missing from Settings App

I bought an iPhone 16 two days ago and have upgraded to iOS 18.2.1. I want to use my phone as a clock when at my desk, so I went into my settings to change the StandBy mode to stay on all the time. However, when I went into my settings, this option was unavailable. Additionally, when I went to Display & Brightness, I cannot find the setting to change my display to "always on display." I have restarted my phone, and have been on apple's customer support for about 30 minutes with no luck. How is it possible that I have the newest phone and newest iOS but am missing features of my settings app?