How do I change a reservation on Copa Airlines ?

https://medium.com/@gjf10412/latest-update-how-late-can-you-cancel-a-refundable-allegiant-flight-35aea8f74ec5
https://medium.com/@gjf10412/latest-update-how-late-can-you-cancel-a-refundable-allegiant-flight-35aea8f74ec5
https://medium.com/@gjf10412/latest-update-how-late-can-you-cancel-a-refundable-allegiant-flight-35aea8f74ec5
https://medium.com/@gjf10412/latest-update-how-late-can-you-cancel-a-refundable-allegiant-flight-35aea8f74ec5