Use APKPure App
Get Dark Theme Toggle old version APK for Android
Adds a Quick Toggle to your device's Device Theme setting
Note: This app only toggles the existing Device Theme setting. It will not add dark mode to your device if it's not already supported.
To get started, add the "Device Theme" Quick Toggle to your Quick Toggles panel.
This app works only on Android P and above.
More to come soon ;)