Code-Snippets-Functions/Execute a function on a child site/WooCommerce/hide-coupon-box-on-checkout-if-coupon-already-applied.txt

add_filter( 'woocommerce_coupons_enabled', 'woocommerce_coupons_enabled_checkout' );

function woocommerce_coupons_enabled_checkout( $coupons_enabled ) {
    global $woocommerce;
    if ( ! empty( $woocommerce->cart->applied_coupons ) ) {
        return false;
    }
    return $coupons_enabled;
}