You'll need to contact Knox, they are in Phoenix, and order a key and box from them. They will have your local fire department in their database so the key cylinder they send you works with the local FD keys. The key provides a contact closure that should go to the fire key input on the gate controller. Interesting that the gate contractor is trying to get out of the mix, out here you have to have the FD come out and measure the gate clearance plus test the key to get permit sign off.

[Link: knoxbox.com]