Script - DHCP Client

Hello,
There is a script that updates the IP address in DynDNS and replaces the IP address in the IPv6 tunnel. It is performed in the sheduler every 5 minutes.
There is a provider that gives IP over DHCP and rent for 10 minutes.
I tried to include this script in the DHCP Client, I tried to write the name of the script there as in the case of the sheduler, but the script does not execute.
Are the scripts in the DHCP Client intended for another, or am I doing something wrong?