Hi,

To check the pos order is returned or not, you need to loop through the orderliness and make sure the orderlines have the refund_order_line_id ,

var order = this.env.pos.get_order();
const orderLines = order.get_orderlines();

if (order) {
    orderLines.forEach(orderLine => {
        // Check if the order line has a refunded_orderline_id
        if (orderLine.refunded_orderline_id ) {

//Add your code here

}}

Hope it helps