Hello! I built my game with web gl and uploaded on ichio, then I set sizes of screen that I need (I have vertical game), configured in such a way that the page does not have to scroll down to see the entire screen of the game). but when I opened it on my phone it was small, because sizes that I set on ichio page are to small for my phone. And since I set my sizes of my game screen on ichio page, unity cannot expand the canvas on the phone( what should I do?

You can set in itchio to the game play maximized so in the celphone whould see fine. Remember test how it sees in unity simulator