CI MySQLI Stored Procedure with Last Insert ID as output

I am working with a very simple (or so I thought) process of passing a few inputs to a stored procedure, inserting a record, and then trying to get back the ID of that record that was inserted.

I just now realized that when calling a Stored Procedure, the insert_id is always 0. I have been bashing my head on the desk for a while with that one.

So, now I am trying to figure out how else to do it.

Model Function:

 

Code:

   public function addCustomerToProduct($data){
       $procedure = "CALL addCustomerProduct(?,?,@id)";
       $result = $this->db->query($procedure, $data);
       $newID = $this->db->query('SELECT @id as newID');
       echo $newID;
   }

Stored Procedure:

Code:

CREATE DEFINER=`root`@`localhost` PROCEDURE `addCustomerProduct`(IN in_customerID INT, in_productID INT, OUT insertID INT)
BEGIN
    INSERT INTO order_customer_product (customerID, productID, retailAmountAtPurchase, faceValue)
    SELECT
        in_customerID,
        in_productID,
        p.retail,
        p.faceValue
    FROM
        products as p
    WHERE 
        p.productID = in_productID;
        
        SELECT LAST_INSERT_ID() as insertID;
        
END

This was my last attempt after reading some solutions line but then I get the error:

Code:

Commands out of sync; you can't run this command now

How can I resolve this to get the PK/AI that is generated by this stored procedure?