Allow specific products to be purchase only if a coupon is applied in Woocommerce

Question

I am working on a woocommerce website and I am trying to restrict a product to be purchased only if a coupon is applied for it, so it should not be processed without adding

Answer 1

For defined products, the following code will not allow checkout if a coupon is not applied, displaying an error message:

add_action( 'woocommerce_check_cart_items', 'mandatory_coupon_for_specific_items' );
function mandatory_coupon_for_specific_items() {
    $targeted_ids   = array(37); // The targeted product ids (in this array)
    $coupon_code    = 'summer2'; // The required coupon code

    $coupon_applied = in_array( strtolower($coupon_code), WC()->cart->get_applied_coupons() );

    // Loop through cart items
    foreach(WC()->cart->get_cart() as $cart_item ) {
        // Check cart item for defined product Ids and applied coupon
        if( in_array( $cart_item['product_id'], $targeted_ids ) && ! $coupon_applied ) {
            wc_clear_notices(); // Clear all other notices

            // Avoid checkout displaying an error notice
            wc_add_notice( sprintf( 'The product"%s" requires a coupon for checkout.', $cart_item['data']->get_name() ), 'error' );
            break; // stop the loop
        }
    }
}

Code goes in functions.php file of your active child theme (or active theme). Tested and works.

And in checkout: