Under Collection > Rollable Tables, click on +Add

Create a Rollable Table called "dice" (no quotes)

Add the 1, 2, 3, 4, 5, 6 die face images to this table.  Make sure "Players can roll from table" is checked. The weight is 1 and they don't need a name.

Go to Collection > Macros.  +Add the following Macros:

Name: 1
/roll 1t[dice]

Name: 2
/roll 2t[dice]

Name: 3
/roll 3t[dice]

Name: 4
/roll 4t[dice]

Name: 5
/roll 5t[dice]

Name: Dice
/roll ?{Number of Dice|1}t[dice]


Make sure they all say "Visible to All Players".   Also click the “In Bar” checkbox and it should add them to the bottom left corner of your Roll20 screen.

If you'd like to add the second set as well, you just have to change "dice" in the above macros to be the name of the new rollable table.