Razer Kishi button mapping

Hey there! Old school Diablo (blizzard) player here. Diablo Immortal (mobile) comes out next week and I look forward to playing it, as my wife is cool with me laying in bed playing on my phone, but not a fan of me spending endless nights in my computer room. I went ahead and ordered a Razer Kishi after seeing a couple videos on it. The only question I still have that isnt answered or discussed on any videos or their website is button mapping https://tutuappx.com/. Are the buttons automatically going to sync to specific actions from the game? And if so, is there any way to change it? Example, if I load up Diablo and my character has 4 skills... are the going to default to Y X A B? Or if I want to set my Ultimate skill to, lets say, right trigger... will i be able to do that?