App Permissions - from "allowed only while in use" to "allowed all the time"

[stay healthy]

Hi, I have the S21. I noticed that the app permissions are now slightly different from my Samsung A8. Some Apps have permissions that are "allowed all the time", while some apps are "allowed only while in use". I tried to change the app permissions, but when I tap on certain apps, I only find 3 options - "allowed only while in use", "ask every time" and "deny". What happened to being able to select "allowed all the time"? That option seems to have been removed for most apps. I would like the permissions on some of my apps to be "allowed all the time", so that I can receive relevant notifications. Appreciate any tips/advise. Thanks!