Bereavement fare is only provided by a few airlines and to eligible travelers. So, when you are looking to take advantage of this Bereavement Flights benefit from the airline, you get to submit all the documents to the airlines that offer bereavement fares for verifications. So, the information on the required documents is as such:
Relation of travelers with deceased person
Name of deceased person
Funeral home, hospital, or hospice names and contact number
Doctor Name (in some conditions)
When the document proves their authenticity, you can purchase their flight tickets.