How to send the ticket change email?

how to send an email to change the ticket: call the company that sold you the ticket and ask for a change. However, please remind me that if you buy a discounted ticket, you must pay a change fee. If it is a special ticket, it cannot be returned or changed. If you need to change your visa or refund your ticket, it means that you will lose all the expenses, but the airport construction fee of 5 yuan can be fully refunded.