Note:
This guide is applicable to customers on LimeSpot Max, Premium, Essentials, and other legacy plans.
Open the Designer by going to Conversion > Website Personalization and click on the black Designer button.
Add any item to cart, then navigate to the cart page of your site.
Click on the Upsell box on the left hand sidebar to open the box settings and in the General Settings, in the Upsell pane, select Random every time from the Order dropdown menu.
Remember to Save and Publish.