Use APKPure App
Get Mongolian Keyboard old version APK for Android
Możemy napisać tekst w naszym ojczystym języku.
it has layout like pc keyboard locations. so when write something on your phone you can use your tow hand.
Settings->Language & keyboard -> Mongolian keyboard -- check it.
after that when you write something, long press on text input and choose Input method -> Mongolian keyboard