How do I add a custom page to my slideshow?

When you create a slideshow, you can select all parts of the slideshow from your product walls, custom pages and videos. Custom pages are the second category, shown in purple. Here you can search by name for the page you want. You add these by clicking on the plus sign and selecting the different devices/screens you want to play the page on. You can adjust the timing of the playback in the timeline. This is done by dragging the bars, or by clicking on the arrow at the bottom right and entering the number of minutes and seconds.