I decided to create both IPv4 and IPv6 addresses.  I disabled dhcp.    Fortinet doesn’t do DHCPv6 reservations.  I can’t match IPv4 to IPv6.

A Boolean represents a true/false value. Booleans are formatted as English words (“true”/“false”, “yes”/“no” or “on”/“off”) for readability and may be abbreviated as a single character “y”/“n” or “Y”/“N”.

They moved the network configuration to here: etc/netplan$ sudo vi 01-netcfg.yaml

network:
version: 2
renderer: networkd
ethernets:
ens32:
dhcp4: false
dhcp6: false
addresses: [192.168.1.65/24, ‘fd00:192:168:1::65/64’]
gateway4 : 192.168.1.173
gateway6 : fd00:192:168:1::173
nameservers:
addresses: [208.91.112.53, 208.91.112.52]

Sudo netplan try: tests it
Sudo netplan apply : enables it.