Here's how you can do add Banner Images to your Online store.
From the left panel in your Dashboard select -> Online store -> Store Settings > Edit Theme -> Slider Image
✓ on Slider enabled if you want all the images to be in sliding motion on your store website and add the following details.
Image: Upload image that you would want to show on your store home page as a banner image.
Update heading: Heading will be placed in the middle of the image.
Subheading: Subheading will be placed under the heading in the middle of the image.
Link: Link the image with a URL page. The URL page will be the landing page where the visitor can click on the image and land on the linked page.
Type of Slider: Select App or website or both options based on which platform you would want the images to be a slider type. Say for example: - if you choose a website all the banner images will be a slider type.
You can upload a maximum of 10 Images.
Check out your Online Store to View the updated Banner Images on your Store
Here's how your Banner Images are shown on your Store home page