Thank you for the reply johnp, they are using 2 CO lines so I have plenty of open ports but there is no service for them. Could you explain how I would use one of the incoming ports to connect to and use the PA through please. I can't "see" in my head how I would run the connections. I just don't have enough phone experience.

Would I plug the PA into one of the incoming ports then select that "line" to send a page?

I don't see anything about a dial 9 group. I did have to tell it what lines actually had a CO connection though.