I cant press the button, and haven’t been able to since downloading. Anyone know anything about it or how to fix?

Hi and welcome to forum

this icon just tell you that monsterwood have gems where you watch ads and get 1 gem each

But to have this feature in the first place -- mean monsterwood - your game should be 20 day old so if you just started you have to wait 3 weeks before you can get gems from it