There are two ways to access PlayPosit in Canvas. One way is by selecting the PlayPosit app in your Rich Content Editor menu in Canvas. This way will not sync a bulb's grades with a graded Canvas Assignment. The other way is selecting PlayPosit as an 'external tool' submission type in your Canvas Assignment. This way will syncs the bulb's grades to the Canvas Gradebook.
See below for PlayPosit's instructions on accessing PlayPosit in Canvas: