First spawn an actor (perhaps to the background) with a 'display text' behavior. You can add a timer or rule to this actor so it spawns at a specific time or after a specific event. Then create a timer on the actor: 'after x seconds' with a 'destroy' behavior.
I'm new to GS so someone else might be able to give a more detailed answer.
Comments
I'm new to GS so someone else might be able to give a more detailed answer.
Set some seconds.
Add your display text function.
Done.