How to set up a promotion that automatically adds a specific product to the cart when a customer spends a certain amount?
While you can offer a product to a customer based on the value of their cart, Upsell does not automatically add the product to the cart. Customers must decide to accept or decline the offer on their own.
You can add a cart value condition to your offer when creating your Upsell offer. For step-by-step instructions, please visit: https://support.boldcommerce.com/hc/en-us/articles/20282638813588-Create-a-Cross-sell-Offer