Figure out how Xamarin works:
https://docs.microsoft.com/bg-bg/xamarin/get-started/
Figure out how Android Development using Kotlin works.
And decide which way is easier to solve.
Also in both cases you would have to figure out how to connect to the db of Gaska we
Also if I want to connect the android app to my sql server database I would have to create some sort of a web service (Restful?)