Duckdns script on Mikrotik v5.26

Hello everybody, I am trying to run the script provide from Duckdns but I am getting errors. below is the script

:global currentIP;
:local newIP [/ip address get [find interface="ether1"];
:if ($newIP != $currentIP) do={
    :log info "IP address $currentIP changed to $newIP";
    :set currentIP $newIP;
    /tool fetch mode=https url="https://www.duckdns.org/update?domains=mydominio&token=63r2d181e-8d2d-4fsd-965f6-842fb12bb392&ip=$newIP" dst-path=duckdns.txt;
    :local result [/file get duckdns.txt contents];
    :log info "Duck DNS update result: $result";
}

I tried to check line by line in console and I think the problem is on line “/tool fech mode=https …” because I get sintaxis error. it seems like mode=https is not valid.
someone have any idea why it is not working.
Thanks in advance.

https mode is not supported in ROS v5.
It was added recently in ROS v6, so upgrade to latest v6 version.