On the bar just above the keyboard there is a plus sign. Not the one at the top RHS of the app. This gives a number of options including page breaks and line breaks. This will insert the page break at the current cursor/insertion point. However I haven't yet worked out how to move the insertion point down to the bottom of a page full of inserted pictures. Anyone know?
Have you made all your images unrelated with text? I mean, you select an image, go to format, select "adjust-none", send it to the background, and thats all... then, you can add a page jump or whatever you call it in english (sorry, spanish language user).
And what do you do when there is no keyboard displayed? I was able to insert pages by tapping on the screen until,the keyboard was displayed, but that stopped.
Kind of tired of people's smug "you just do this" responses. It isn't always that easy until you get it to work.