You can absolutely do this. Whenever the Google Play releases the latest version of the app that you've sideloaded, it will commence an update.
There might be several reasons for installation errors. Errors can appear when you try to download an APK:
- with a lower version than the one which has already been installed. It means that you are trying to downgrade without uninstalling the current app first.
- with a cryptographic signature which doesn't match the already installed one.
- to install in a different CPU architecture. If you are using a 32-bit arm device, it's impossible for you to try to install an apk file with arm64 libs inside. On the contrary, the 64-bit arm is compatible with all devices, even 32-arm ones.
To know exactly what DPI and noDPI mean, click here to read our detailed post - arm, arm 64, x86... are CPU architectures. A 64-bit device can install both a 64-bit APK and a 32-bit apk, but not vice versa.
To help you know how to check your device’s DPI, screen size and other specs, we have prepared a detailed post, click here to know more.