/**
 * @snippet       Edit "Have a Coupon" message @ WooCommerce Checkout
 * @author        Shadowtek Web Solutions
 * @compatible    WooCommerce 5
 */
 
add_filter( 'woocommerce_checkout_coupon_message', 'stek_have_coupon_message');
 
function stek_have_coupon_message() {
   return '<i class="fa fa-ticket" aria-hidden="true"></i> Have a coupon? <a href="#" class="showcoupon">Click here to enter your discount code</a>';
}