I'm pretty sure you need a higher version of Android for Good Lock to work. If you are on Android 9, you have a very old, unsecure phone and you should upgrade if you can. I do realize that many people simply cannot afford to upgrade or are loathe to abandon a phone that is working well for them, but when a phone can no longer do what you need it to do (and soon, most secure apps will simply stop working), it is time to explore other options.
