highscore on mobile

Hello everyone, i am pretty new in Unity C# programming. So my game is almost finished, but i have a problem with my highscore. On computer everything works fine, the highscore gets updated. But as soon as I drag the apk version to my phone, the highscore doesn’t gets updated. Does someone know why? Would be happy if I get answer :smiley:

Are you using Playerperfs?

This is basicly the part where I wrote the high score: