The game should be compatible with any Android version from 7.0 to 15.0. Unless you're below 7.0, you should be able to ignore the message and install/play the game anyway.
I tested the game on Android 7, 10 and 15, it worked fine on all of them. You might have to check your phone's security settings and/or uninstall any prior versions of the game first, both are known to cause trouble with software from external sources. Hope that helps
