Wrong order number in Gateway plugin

Hi all,

please, I need your help to fix a problem with the gateway payment plugin of my site.
The number of order is wrong on the gateway window, I read around the web that the plugin by default takes the sequential number of post.

Installing your plugin, I change the sequential number of my order to EC-0001, EC-0002, etc…
How can I put this order also on the gateway plugin?

The point on the code where I think we have to modify the code is:

global $woocommerce;
$order = new WC_Order($order_id);

I try changing:
$order = new WC_Order($order_id);

with:
$order = wc_get_order( $order_id );

but it does’t work at all.

Thanks in advance if someone can help me.