Static netplan yaml error messages

strong textI miss the old /etc/network/interfaces means to configure IP addresses.

My file is located in /etc/netplan/ The configuration is:

network
  version: 2
  renderer:networkd
  ethernets:
    ens33:
    dhcp4: no
    dhcp6: no
      addresses:
        - 172.16.10.254/24
      gateway4: 172.16.10.1
      nameservers:
          addresses: [8.8.8.8,8.8.4.4]

The error message is, "Invalid YAML at /etc/netplan/50-cloud-init.yaml line 12 column 15:mapping values are not allowed in this context.

That would mean the error is ith the string gateway4: 172.16.10.1.

I've searched The InterWeb for possible errors and have seen multiple configuration styles, which confuses me.

When I execute sudo netplan apply I receive the same message about mapping and contexts.

When I execute sudo netplan --debug apply I receive the same message.

I've tried with and without DHCP messages (with false and with no).

This is the last error in the file and I am flummoxed. :(

I'd sit on a cattle prod if I thought it would help but I'd prefer not to ... Any tips?

Regards, Dale