Having only cancelled flights for corporate travel that were under my name, I could use a little help understanding American airlines cancellation process.

Scenario:
I plan to pay for and book flights on American for 4 people. All would be booked as Main Cabin tickets (not basic economy). If a passenger other than myself is unable to travel and I cancel just the one ticket, after paying the $200 change fee who can use the remaining credit? Since I paid for it would I be able to use it or can only the ticketed passenger use the credit? This is for travel in the future so (hopefully) none of the Corona virus waivers will be applicable.