If a product can be added to the cart without using a required option, it usually means that the theme is using an AJAX add-to-cart function.
An AJAX add-to-cart function keeps the user on the product page when the add to cart button is clicked, instead of directing them to the cart page. This functionality tends to bypass certain functions of the app, and one of the issues it can cause is bypassing the usage requirement of an option.
Note: "Buy Now" or dynamic checkout buttons are also incompatible with Product Options. These buttons skip the required 'add-to-cart' functionality needed for our app to ensure that the options are properly added to your customer's order.
To fix this, disable the Ajax add-to-cart functionality in your theme:
- From Shopify's admin, select Online Store, then Customize next to your the theme that needs to be fixed.
- Select Theme settings > Cart.
- Under Cart type, select Page.
- Select Save.
If this doesn't work, or if you'd like to continue using the AJAX cart along with Product Options, please contact our Merchant Success team.