I recently had to cancel a CO flight and am stuck with $1750 in credit. I normally fly United and Delta. CO is not on any of my regular routes so I don't know how I'll manage to use this credit. Two questions:

I have a friend who needs to book an expensive CO flight. Can I use my credit to purchase for him? Does it matter whether it is friend or family?

I do use Delta occasionally. They are now code sharing with CO. Could I use the credit to purchase Delta tickets.

Any thoughts or advice is greatly appreciated.