How to add background images to front page of Pages doc? Want to add background images to the front page only of a Pages doc.

I can't understand how to do this—reading the Apple doc on this didn't help unfortunately. Can't get background images (Master Objects?) working at all.

Using Pages 6.2.

Also noting that Arrange > Section Masters > Move Object to Section Master is greyed out...
Make the front page its own section. From the Document Setup inspector, choose
Section → Create a new section.
Add your image to the front page and position it how you desire.
With the image still selected, choose
Arrange → Section Masters → Move Object to Section Master