Is there a way to add background-image to theme.json?

Background image in theme.json is not yet supported

In your theme.json file, you can define a CSS class name for the element that you want to add the background image to. For example:

"styles": {
  "hf-bg": {
    "backgroundColor": "#ffffff"

In this example, we’ve defined a style called hf-bg that sets the backgroundColor property to white. You can then add custom CSS to your theme to apply a background image to this element. For example:

.hf-bg {
  background-image: url('assets/images/hf_bg2.png');

This CSS will apply a background image to any element with the class hf-bg. Make sure to adjust the URL to the location of your image file relative to your theme’s root directory.