To cancel booking contact Copa Airlines customer service or go through Copa Airlines Cancellation Policy for more details. Copa Airlines allows free cancellations within 24....
https://www.tripstrolly.com/blogs/what-is-the-copa-cancellation-policy

To upgrade seats in Eva Air go through the option Eva Air Upgrade. Eva Air offers upgrade options for passengers seeking enhanced comfort and services.....
https://www.getlowfare.com/blogs/eva-air-seat-upgrade