You can require the user to add certain products to the cart.
To enable this feature go to Catalog Settings > Shopping Cart and find the Product Dependency section:
Once you check the Enable Dependencies checkbox, it will enable the feature.
Now you will see the Depends On box on the product edit screen:
You can select an unlimited number of products that the customer should select with this product.
Now when the user adds to the cart a product with selected dependent products, he will not be able to proceed to checkout without selecting additional products first:
You can fully customize the message that shows up if the user didn’t add the required products to the cart.
To customize the message go to Catalog Settings > Shopping Cart and find the Dependent Products Info text area:
Change the product dependency logic.
By default, you must add all the required products to the cart. You can change the logic to require only one of the specified products.
You can do it in Catalog Settings > Shopping Cart in the Product Dependency section:
Once you switch it to OR, it will require only one product instead of all of them:
