I solved it using the v-add-sys-ip command, I just added the IP, followed by the NETMASK, something like this:
v-add-sys-ip 123.456.789.0 255.255.255.255.255
The other values were filled in added in automatic, and set to shared (can be modified from the Hestia panel).
A reboot was necessary right away, because it was still not working until I completely restarted the server.
Thanks!