newbie lab - cannot make snom 821 to manually provision

[imcontreras]

Phone Type: snom821-SIP
VPN: Off
MAC-Address: 0448C4C31F69 (fake address, just for illustration)
IP-Address:10.0.10.93
IP-Address(v6):
Firmware-Version:snom821-SIP 8.7.5.35

My current Orig and Term provider it's VoIP Innovation.
My VPS Debian 9.4 x64
Fusion PBX v 4.4.3

Extension settings:




issue:
Device Provisioning, cannot make the devices to manually provision.

I'm following the instructions on this URL: http://docs.fusionpbx.com/en/latest/applications/provision/provision_manual_snom.html

My phone setting


this is the setting URL:

http://105.249.117.55/app/provision/index.php?mac={mac}

I also try this:

http://105.249.117.55/app/provision/index.php?mac=0448C4C31F69

I also try this:

http://105.249.117.55/fusionpbx/app/provision/index.php?mac=0448C4C31F69

and this:
http://105.249.117.55/fusionpbx/app/provision/index.php?mac={mac}


running sngrep command: I cannot see any request from the phone
running iptables -L -n command: my IP is not in the REJECTED list, I have my IP whitelisted on the Access Controls

I've another grandstream phone I was able to provision and works fine.

once again, if anyone has a tip I'll be very thankful.