Help adding ssh key remotely using a script

I am adding ssh-keys using a script with these commands.

/opt/vyatta/sbin/vyatta-cfg-cmd-wrapper begin
/opt/vyatta/sbin/vyatta-cfg-cmd-wrapper loadkey ubnt_id_rsa.pub /tmp/ubnt.pub
/opt/vyatta/sbin/vyatta-cfg-cmd-wrapper commit
/opt/vyatta/sbin/vyatta-cfg-cmd-wrapper save
/opt/vyatta/sbin/vyatta-cfg-cmd-wrapper end

I get an error saying : Invalid command "loadkey" for vyatta-cfg-cmd-wrapper

Thanks for the help.