Configure Portal server ntp service.
Debian 12 portal server
Debian 12 default does not use ntpd but use systemd-timesyncd for sync tine with network. So /etc/ntp.conf file could not exist unless ntp is installed.
The Debian 12 default uses systemd-timesyncd for time service. It can be configured in /etc/systemd/timesyncd.conf.
Edit the file and set you timer server ip(s) (or FQDNs space separate mutiple ip or FQDN) at
NTP= <network ntp servers>
and
FallbackNTP= <network ntp servers>