3CX Software 15.5 License

[RazorATX]

I am trying to connect a Paxton Panel to the 3CX extension. Software version 16 but it does not allow authentication. So I tried to revert to V15.5 because I know this one works at a different site. The problem is that my free license does not work for 15.5 now.
Any help is welcome.

 

[Saqqara]

Ver 15.5 is end of life, you will not get a license for this version

What issues are you having , with the Paxton panel

 

[leejor]

Same, similar , system?...
https://www.3cx.com/community/threa...sip-server-with-door-entry-panel.76105/page-2