The recent version allows adding custom content to the top of the shop page:
1. Enable Top filters in the Theme Settings >Product archives > Shop filters https://gyazo.com/3564df2a5d658a0010b6c0ebd0b537d4
2. Enable Shop filters area always opened
3. Shop filters content type should be set Custom content
4. You can choose the HTML block with the content from the Shop filters custom content drop-down.
You can create the banner in the HTML block by means of the builder you use in the site.