Changing Scale in Layout

I haven’t used SU or layout for about a year and having a very senior moment. I have forgotten how to change the scale in Layout of the viewpoint I imported from SU. It is at 1:100 and I want it 1:50. I can’t seem to find the window to do it. Have I somehow managed to lose the window? Thanks All

SketchUp Model panel (right side)

Fantastic thank you. I had somehow managed to switch off the camera bit!