https://intercom.help/airlines-support-aefaa9296861/en/articles/10820289-ua_flights-how-do-i-know-if-my-united-economy-ticket-is-refundable
https://intercom.help/airlines-support-aefaa9296861/en/articles/10820289-ua_flights-how-do-i-know-if-my-united-economy-ticket-is-refundable