add_shipping on wc_create_order (woo commerce) - woocommerce

Question

I have successfully able to create an order through functions.php file.
I need help adding the free_shipping into the order. Can you please help with this one line?
The code I used to create an order on functions.php:
$lp_order = wc_create_order();
$lp_order->add_product( get_product( $lp_product_id ), 1 ); //(get_product with id and next is for quantity)
$lp_order->set_address( $lp_address_full, 'billing' );
$lp_order->set_address( $lp_address_full, 'shipping' );
$lp_order->update_status('processing');
$lp_order->add_shipping();
On the last line, what array should I pass to the add_shipping function? I tried using
$lp_order->add_shipping('free_shipping');
but it does not work.
Full code on functions.php
function lp_create_order() {
$lp_email = $_POST["lp_email"];
$lp_firstname = $_POST["lp_firstname"];
$lp_lastname = $_POST["lp_lastname"];
$lp_phone = $_POST["lp_phone"];
$lp_address_1 = $_POST["lp_address_1"];
$lp_address_2 = $_POST["lp_address_2"];
$lp_city = $_POST["lp_city"];
$lp_state = $_POST["lp_state"];
$lp_postcode = $_POST["lp_postcode"];
$lp_product_id = $_POST["lp_product_id"];
if ( isset( $lp_product_id ) ) {
$lp_address_full = array(
'first_name' => $lp_firstname,
'last_name' => $lp_lastname,
'company' => '',
'email' => $lp_email,
'phone' => $lp_phone,
'address_1' => $lp_address_1,
'address_2' => $lp_address_2,
'city' => $lp_city,
'state' => $lp_state,
'postcode' => $lp_postcode,
'country' => 'CA'
);
$lp_order = wc_create_order();
$lp_order->add_product( get_product( $lp_product_id ), 1 ); //(get_product with id and next is for quantity)
$lp_order->set_address( $lp_address_full, 'billing' );
$lp_order->set_address( $lp_address_full, 'shipping' );
$lp_order->update_status('processing');
//$lp_order->add_shipping('free_shipping',0);
//$lp_order->calculate_shipping();
$lp_order->calculate_totals();
print "Order is placed";
} // end if
} // end lp_create_order
add_action( 'init', 'lp_create_order' );

Answer 1

For the order's add_shipping method, this is what i was able to successfully pass through on Woo-Commerce 2.6
$ship_rate_ob = new WC_Shipping_Rate();
$ship_rate_ob->id=0;
$ship_rate_ob->label='Free Shipping';
$ship_rate_ob->taxes=array(); //not required in your situation
$ship_rate_ob->cost=0; //not required in your situation
$lp_order->add_shipping($ship_rate_ob);
I am setting the shipping rate's id to 0. It is working for now but I would recommend setting it to an existing free_shipping rate in your database. You can find your shipping rate's ID in the url of it's edit page.

Answer 2

add_shipping() expects WC_Shipping_Rate array, Use Woocommerce default free shipping package for this.
do some thing like this.
$lp_order->add_shipping(
array (
'id' => 'free_shipping',
'label' => "Free Shipping",
'cost' => 0.00,
'taxes' => array(),
'calc_tax' => 'per_order'
)
);

Answer 3

Try this for the shipping:
$shippingAddress = array(
'first_name' => $lp_firstname,
'last_name' => $lp_lastname,
'company' => '',
'address_1' => $lp_address_1,
'address_2' => $lp_address_2,
'city' => $lp_city,
'state' => $lp_state,
'postcode' => $lp_postcode,
'country' => 'CA'
);
Just remove email and Phone and you're good.