Handle access to order delivery process page

backend/app/plugins/wiaas/includes/admin/delivery-process/class-wiaas-admin-delivery-process-flow.php

@@ -23,6 +23,15 @@ class Wiaas_Admin_Order_Process_Flow {
     public static function output_delivery_process() {
 	    $order_id = absint( $_GET['id'] );
 
+	    $has_access = Wiaas_Access_Management::can_current_user_read_order($order_id);
+
+	    if (! $has_access) {
+
+		    echo "<h2>You don't have permission to view this order.</h2>";
+
+		    return;
+	    }
+
 	    $order = wc_get_order($order_id);
 
 	    if ( !$order ) {