Which sheet are you using? I'm guessing OGL. By default, it rolls 2 d20s so you can evaluate the action as normal (use the first one), advantaged (use the higher), or disadvantaged (use the lower) on the fly. You can change that in the gear tab. I believe you can also set the default on the Game Settings page where the Character Sheet is selected at the bottom. Here's the relevant wiki section: <a href="https://wiki.roll20.net/5th_Edition_OGL_by_Roll20#Rolling_for_Advantage_and_Disadvantage" rel="nofollow">https://wiki.roll20.net/5th_Edition_OGL_by_Roll20#Rolling_for_Advantage_and_Disadvantage</a>