You can add, change, or delete configuration variables in the Configuration Mode. You can enter the configuration mode using the configure command. To exit from the configuration mode, enter the exit command.
If you enter the help command in the configuration mode, you can see all commands of the mode.

LYSH@MyHostName# configure
LYSH@MyHostName(config)# help

Documented commands (use 'help -v' for verbose/'help <topic>' for details):
===========================================================================
database  dhcpv6    help      ip      loghost     ntp     timezone
datetime  fail2ban  history   log     nameserver  rtlog   ufw
dhcpv4    failover  hostname  logexp  netplan     system  user

database

Please refer to the CLI - Database section.

datetime

Please refer to the CLI - System section.

dhcpv4, dhcpv6

Please refer to the CLI - Services(daemons) section.

fail2ban

Please refer to the CLI - fail2ban section.

failover

Please refer to the CLI - System Failover section.

hostname

Please refer to the CLI - Hostname section.

ip

Please refer to the CLI - Networking section.

log

Please refer to the CLI - Log section.

logexp

Please refer to the CLI - Services(daemons) section.

loghost

Please refer to the CLI - Log section.

mysql_tls

Please refer to the CLI - Database section.

nameserver

Plese refer to the CLI - Networking section.

netplan

Please refer to the CLI - Networking section.

ntp

Please refer to the CLI - NTP section.

rtlog

Please refer to the CLI - Services(daemons) section.

system

Please refer to the CLI - System.

timezone

Please refer to the CLI - System section.

ufw

It is the default firewall configuration tool. Please refer to the CLI - ufw section.

user

Please refer to the CLI - User and Session section.

References