The Scale of the peg needs to be set to separate instead of locked

When importing a .png file for my background, I cannot transform it or use the perspective tool (because it will move in the animation) effectively. This message box pops up and I do not know where to find the Peg Editor dialog when using Google Search and looking at other help requests.

In Harmony Essentials you can change layer’s transformation properties from the Timeline
Double click on the layer properties icon and change scale type