Add a shipping to an order programmatically in Woocommerce 3

I've been trying numerous solutions to programmatically set the price of shipping (per order) via Woocommerce. I'm having no luck

I have tried overwriting the meta value for the item:

            update_post_meta( $woo_order_id, '_order_shipping', $new_ship_price );

Also tried something along the lines of this [Question/Answer][1]

                    $item_ship = new WC_Order_Item_Shipping();

                    $item_ship->set_name( "flat_rate" );
                    $item_ship->set_amount( $new_ship_price );
                    $item_ship->set_tax_class( '' );
                    $item_ship->set_tax_status( 'none' );


                    // Add Shipping item to the order
                    $order->add_item( $item_ship );

But neither seem to work. Any pointers most welcome.

Similar thread: Add a fee to an order programmatically in Woocommerce 3

Solution 1:

To handle this in Woocommerce 3+ use the following (from a WC_Order Order object $order):

## ------------- ADD SHIPPING PROCESS ---------------- ##

// Get the customer country code
$country_code = $order->get_shipping_country();

// Set the array for tax calculations
$calculate_tax_for = array(
    'country' => $country_code,
    'state' => '', // Can be set (optional)
    'postcode' => '', // Can be set (optional)
    'city' => '', // Can be set (optional)
);

// Optionally, set a total shipping amount
$new_ship_price = 5.10;

// Get a new instance of the WC_Order_Item_Shipping Object
$item = new WC_Order_Item_Shipping();

$item->set_method_title( "Flat rate" );
$item->set_method_id( "flat_rate:14" ); // set an existing Shipping method rate ID
$item->set_total( $new_ship_price ); // (optional)
$item->calculate_taxes($calculate_tax_for);

$order->add_item( $item );

$order->calculate_totals();

$order->update_status('on-hold');

// $order->save(); // If you don't update the order status

Tested an works.