What you are showing should be on the left side of your screen.
As I said before, you have to choose the correct screen on the top right corner in the drop down. Seems like you have the welcome screen open. The welcome screen does not have questions on it, thus no question.pstpl is available.

Once you picked the template, you need to choose the screen right next to it. Once you choose the question screen, you will also see the question.pstpl.