How dose morph into dinosaurs work?

I was playing the game morph into dinosaur made by kreating studio and I don’t understand how to transform cuz I can get into the menu then I can only get out by shifting. And every other button dose notching.

I have a nitendo switch not a pc

What button DuPont I need to press?😭

If it doesn’t work I want a different game but I can’t cuz all the minecoins are gone cuz of the purchase.