Exclude Products from Specific Categories

Hi!

I have a products with add on products in it. And I wanted to limit only two products in my cart. How can I exclude the add on products? Because currently when I set the cart limit to 2, it automatically gives an error when I’m adding multiple add on products I have 6 add ons for all products.

Please check here https://ssptesting.com/americanwhirlpool/product/american-whirlpool-100-spa/. The add ons are the checkboxes under Spa Upgrade and Spa Accessories.

Thank you!