Hero Banner Component
You seem to have created a new Hero Banner Item - "HomePageBanner" but need to assign Content Items list to it.
Click anywhere on this box to see the Context menu in Top Left or Bottom Left.
Add existing Content Items
Create New or Add Existing Parent Component Item
Save Edits done
- Select Content Items from the Context Menu and Save it to view the newly added items OR
- Click on "Add New Content Item" button above