Thank you for your reply.
Regarding your comment that “to apply a coupon, a main product must always be included in the cart”, in WooCommerce core this is not enforced through any special processing. When the cart is empty, the coupon input field is simply not displayed due to its placement in the cart UI, but there is no underlying check for the existence of a main product.
On the other hand, WPC Free Gift Coupons is not a discount mechanism, and as stated in your official description, it can “create independent free gift coupons.” However, in the current implementation, the remove_invalid_free_gifts_from_cart function contains custom logic that removes gift items when no regular product is present in the cart. This is not part of WooCommerce core behavior, but rather a plugin-specific condition.
That said, if this is the intended WPC specification and standalone use is not supported by design, then we understand and will accept that.
Thank you for your time and consideration.
