There's no simple answer to this.

What was the flight and when was it?

The Ts & Cs say Holds are available on "Select" flights. I've found they sometimes aren't offered on AA marketed flights offered by other carriers.

Also, I've found that generally if the flight is less than one week away, Hold isn't available. For example, I just looked at trying to hold AUS-LAX for November 14th (6 days from now) and no Hold offered. November 15th, Hold is offered.