Hi, that is correct, you need an adapter board to with that combo as explained in the instructions ("You can use the Brickstuff power connector with any adapter that has a large connecting plug (like our BRANCH04 or BRANCH11) to connect to the same power source as your other lights or effects.").  Here's the one you need.

Daniel Donnelly , thank you for ordering that adapter-- I refunded a large part of your shipping charges today as you shouldn't have been charged that much to ship just one small part.  You should see the refund appear soon.  Thanks again!