Free shipping code won't work

I am having issues getting a free shipping code to apply itself to the final total. I’ve created the correct coupon and have followed the steps provided by WooCommerice but when I apply it, no discount is given. I can see the code is applied, but the $ is not being taken off the total. I can also create a coupon with a 10% discount and that works, but free shipping won’t. Any help would be much appreciated!!

https://ww.wp.xz.cn/plugins/woocommerce/