If you want to add a text over an image/image under text, follow these steps:
- Add a Text element.
- Select the Text element's parent Box in the treeview on the right side.
- Add and set background image, using the Element Background settings in the bottom-right.
- Under the image there is repeat option. Set it accordingly.
- Add whatever text you like.
- Adjust the padding of the Text element to position it on the image.
- Add padding to the Box element (Element Position settings), so that it has enough space for your image. (Your image might get cropped otherwise.)
Here is a video tutorial.