Move image behind text in Pages

In order for the background <-> Foreground slider to be activated, you need two objects present in the document, and body text is not one of them. When I insert a Text box (Shape > Text) into the existing Pages for iPadOS document, that Text box becomes the foreground layer, and the existing image in the document is automatically shifted to the background object layer. You can also change the Text Wrap to None so you can overlay document objects through layer manipulation and dragging.

The ability exists to emulate the Pages for Mac Move Objects to Section Master, effectively placing an image below text on every page of the word processing section like a watermark. But not with an image already in the document, it must be selected from outside the Pages document and added via the Background panel.

You cannot move an image behind body text, but you can move an image behind a text box.

Uncertain if you can do the latter in Pages in iPadOS, but you can change Text Wrap in the Pages for Mac Arrangement tab and set Text Wrap to None. That allows you to alter the layer of the image and text box. Pages for Mac can also move objects to section master, so you can assign an image on all pages of a section behind body text.

Still another half-hour until dawn here, so limiting my movement in the house until then, and experiment with my iPad Pro running Pages v11.1 and iPadOS 14.8. I principally use Pages for Mac, so not clear what the iPadOS version permits one to do with layers.