Not Adding to Cart, Page just Refreshes

Everything is up to date with the latest version, I disabled every plugin except for woocommerce and this plugin, I even defaulted to the storefront theme, and I still cannot get this plugin to work. The pop-up is there, and I click the box for the 1 free gift item, and click add gift, the page refreshes, the free gift is not in the cart, and the popup is there once more. Please help.