Why do some phones say device not compatible?

I tried installing my game on a few different phones, it works fine on 3 of them but phones like Huawei Y6 and Huawei P9 lite mini say device not compatible. What setting do I need to change to make them compatible. My phone from 2015 is older than those two phones and the game works on it so I assume they should also work.

Most likely minimal API Level in application manifest as usally ue4 shows popup with reason in other cases

https://source.android.com/setup/start/build-numbers

http://www.dre.vanderbilt.edu/~schmidt/android/android-4.0/out/target/common/docs/doc-comment-check/guide/appendix/api-levels.html

You need to set the target level atleast to 26, minimal can be lower, but keep in mind the lower you go the higher chance game won’t work, the higher version of UE4 the less chance it will work in older devices. I run early UE4 projects on 4.0 and 5.0 devices with ES2