How to stop android software update without notice?!

I'm livid. Just missed an important work call because my S21 decided to update itself without notice at 12:30pm today. Sure I had the notification that a software update was required but didn't think it would just go off on its own. How do I stop this insane behavior?

When you go to settings>software update>you see toggle for automatic over wifi?
Usually it gives a option to schedule later or download now

I'll leave a Link to register so you can communicate here, As a guest account you can only post questions but can't reply
https://forums.androidcentral.com/sh...d.php?t=409154

I set mine to update when I'm sleeping.