Thanks for posting back.
For closure, the problem you were having is that the Dynamic VPN only works between different machines on the same account. If you want to connect machines on different accounts you need to either use OpenVPN or the Static IPsec VPN or configure IPsec (libreswan) manually.

In the end I created a vpn via openvpn, everything works just fine, even with several reboots

I reinstalled dynamicvpn and now the command returns me:
[root @ gateway /] # systemctl status ipsec.service
● ipsec.service - Internet Key Exchange (IKE) Protocol Daemon for IPsec
    Loaded: loaded (/usr/lib/systemd/system/ipsec.service; enabled; vendor preset: disabled)
    Active: active (running) since Thurs 2019-03-21 12:20:35 CET; 9s needle
      Docs: man: ipsec (8)
            man: pluto (8)
            man: ipsec.conf (5)
   Process: 6566 ExecStartPre = / usr / sbin / ipsec --checknflog (code = exited, status = 0 / SUCCESS)
   Process: 6563 ExecStartPre = / usr / sbin / ipsec --checknss (code = exited, status = 0 / SUCCESS)
   Process: 6301 ExecStartPre = / usr / libexec / ipsec / _stackmanager start (code = exited, status = 0 / SUCCESS)
   Process: 6299 ExecStartPre = / usr / libexec / ipsec / addconn --config /etc/ipsec.conf --checkconfig (code = exited, status = 0 / SUCCESS)
  Main PID: 6579 (pluto)


but system offline is always present and I cannot configure the service

Thank you!

If i execute service ipsec status the console gave me: Unit ipsec.service could not be found.
it is as if it did not have the ipsec service installed

Your English is better than my Italian. I only ever learned to speak it and not write it.

I have asked the devs about the Dynamic VPN. Can you please confirm is ipsec is running with a "service ipsec status"? Also are you getting the message at both ends of the tunnel?