FreePBX integration to MultiVoip 410 gateway

At my remote site I have a FreePBX who’s IP address is I have a VPN tunnel connecting my two sites. At the headquarters I have a MultiTech 410 VoIP Gateway plugged into my Avaya phone systems. I have channel 3 plugged into a analog station port. My goal is to dial extension 360 at the headquarters and have it ring my FreePBX box and get the IVR. Currently when I call 360 I get the dial FROM my FreePBX box… My MultiTech 410 is configured as an extension… I guess I need to set it up as a trunk?