Academy course little bit confusing

Hey there, Right now I’m trying to go through the Academy course “Become a rapid developer”. In lesson 10.4.4 we are asked to update security for the mobile page but for some reason my mobile page are not shown in security  Anyone now how to fix it? Thank you
1 answers

Check if this page is added to the navigation?Or used by any "show page" in "Microflow"?
If not, "this page" will not be shown in security.