A floating cart is an interactive feature which adds a cart icon on the screen whenever a customer adds any product to his shopping cart.
By default Floating Cart Link functionality will be disabled.
Click on Customize Website from the main menu.
Click on Customize Website.
Click on Settings.
From the Settings drop-down, click on Floating Cart Link and enable the toggle.
When you click on the Add button of a product that you wish to add to the cart, the cart icon appears on your website along with the number of products present in the cart.