there is currently an error where the add to cart function does not work for variant product.

Hi, I am currently experiencing an issue where the add to cart feature for variant products in the product list card is not working.
Could you please tell me what is causing this issue and how to fix it?
https://en.abib.com/collections/face-mask

@yerim The Add to Cart button is working fine, but it should have one additional functionality: when a variant is selected, it should automatically add to the cart instead of requiring the user to click ‘Add to Cart’ again after selecting the variant.