Apply coupon discount via GET method in URL even if cart is empty in WooCommerce

Question

I have a plugin that sends an advocates referral coupon code to e-mails that they enter. When the audience receives this email I\'d like to create a flow where they can clic

Answer 1

use below code to make the coupan valid in any situation

add_filter('woocommerce_coupon_is_valid','coupon_always_valid',10,1);
function coupon_always_valid($valid){
     $valid = true;
     return $valid ; 
}