There are normally 2 cases when checkout-boost offers don't show up:
Case 1: Your store doesn't have a cart page, but the setting is "Show offer on cart page".
After customers add a product to cart, if your store has a quick-shop function and directs customers to checkout page instead of cart page, it is suggested that you should choose the setting "Show offer after customers add matched items to cart"
Case 2: You have tested your offers consecutively, and the offer did not show on the second test
>> Skyrocket your sales and drive more traffic with Checkout Boost now.