Using 3D dice, constantly rolling a D20

I am new to D&D in general and very new to Roll20 as well as being a GM. I discovered the use of the 3D dice and found that it is great to use with the players, however, no matter what I click on the player sheets to make a roll it always rolls a D20. Do you want to roll an attack, easy D20. You want to roll your 1 D6+2 by just clicking on the damage section of the player sheet, too bad we only roll D20's here. If anyone knows how to fix this please tell me because the 3D dice is super fun to use. 

Pretty much everything on the 5e D&D character sheet is a D20.  The only thing I can think of that isn't is the HIT DICE just under Hit Points and just above the attacks.  That should roll the appropriate hit dice for you.

To roll damage, you need to roll the attack, then click on the attack name in the chat to roll the damage. You are just going to keep rolling attacks if you keep clicking on the sheet.  There is of course the built in dice roller in the floating menu to the left, and advanced dice rolls you can do in chat (for instance, you can roll by typing /roll 1d6+2).