I guess there’s nothing you can do about the playstore due to international sanctions against Russia. I guess that’s why google shut down paid apps there.
What you can do is ask for a license switch from google play to Cryptomator apk, and then download the apk from the Cryptomator website and install wizhout google play.
But I have to admit that I am not aware if this is possible (again, international sanctions). But asking cannot be wrong.