If you use the Gutenberg editor, create a post or a page and add the AWB block to your post. Click on the Add button to add a block and find the Background (AWB) block in the list of available blocks or click on the AWB icon to add an AWB block if it is available.
You can add other blocks inside of it to add your content. You can have several AWB blocks in your post, as well as you can have several blocks with your content inside an AWB block.