Beginning with version 9.1.18, CORE Themes can also use a flyout cart that will display when a visitor clicks on the cart tab of their store pages.
To enable this feature, follow these steps:
Log into your Shift4Shop Online Store Manager.
Using the left-hand navigation menu, go to Settings > General > Store Settings.
Once you get to the Settings page, click on the Display Options tab at the top.
In the Global Options section, mark the checkbox labeled "Enable Flyout Cart."
Click Save at the top right of the page.
When someone adds an item to their cart and clicks on the cart tab (located on the right side of the frame), they will see a small popup representation of their cart similar to what's shown in the image.