How to get the order number after submitting the "buy in 1 click" form

Question

I have a 1-click purchase plugin for wordpress. When a client enters a name and email, an order is created in the admin panel. How to display the order number for client in a modal window after placing an order? I have a code that creates an order. It generates an order number after submitting the form. I don't understand how to catch him.

$order = wc_create_order();

        do_action( 'awooc_after_created_order', $product_id, $order, $address, $product_qty );

        $this->add_order( $order, $product_id, $product_qty, $address );

        $this->change_subject( $contact_form, $order );

        do_action( 'awooc_after_mail_send', $product_id, $order->get_id() );