Brand new to roll20, and trying to set up a 5e campaign for some scattered friends. Character sheet is great and once set up, will make things easy. But I can't get the initiative button to work. I thought it would be a dex check (with some possible mods) & record the number. But I'm getting errors (no token selected, for example). I select the token tied to the sheet and... nothing. No matter how many times I click. Nothing. So how is the initiative button supposed to work and what am I doing wrong?