Yes, passengers can change the Name of their United. They can do so by visiting the United website or contacting customer service (OTA) directly. Can....
https://community.sw.siemens.com/s/question/0D5Vb00000JMkarKAD/change-name-on-united-ticket

To communicate with American, call their customer service hotline at (USA)(US) for immediate assistance. You can speak directly with a live representative or explore their....
https://community.sw.siemens.com/s/question/0D5Vb00000JMeIUKA1/hasslefree-how-to-easily-name-change-on-american-ticket-a-detailed-procedureaacom