Just to make some people 😄, I got a bonus feature that I know that works. Did you know you can get Android 10's Digital Wellbeing features to Android 9?
1. Make sure you're on the latest update of your phone (at least have the phone get Digital Wellbeing).
2. Go to the Play Store and search Digital Wellbeing. If it isn't there, search it instead on Chrome.
3. In the app's page, find "become a beta tester" and click join. Wait for a few minutes and update the app.
5. When it's done, go to settings and press Digital Wellbeing.
6. Explore the new features
P.S. It may not work for everyone though. Even if the app is in beta, I can barely see any bugs/issues with it.