ENDIAN Firewall - Can't setup Endian to connect to my OpenVPN site-to-site VPN

Hello.

I'm currently replacing my Vyatta router/firewall by Endian,
Everything is working fine, except the OpenVPN that I can't find how to configure on Endian.
Here is what my OpenVPN configuration looks like on Vyatta :

Code:

    openvpn vtun0 {
        description "Tunnel to v3"
        firewall {
            in {
                name lev-vpn-in
            }
            out {
                name lev-vpn-out
            }
        }
        local-address 192.168.xx.xx
        local-host 81.56.xx.xx
        local-port 11xx
        mode site-to-site
        openvpn-option "--tun-mtu 1400"
        protocol udp
        remote-address 192.168.xx.xx
        remote-host 88.191.xx.xx
        remote-port 11xx
        shared-secret-key-file /etc/openvpn/lev_vyatta.key
    }

I can't find on Endian any equivalent configuration on the web interface, it want a certificate that I don't have, I only have a key file (symetric key).

How can I do that ?
This is the only thing that prevent Endian to completely replace my Vyatta firewall.

Thank you