Write_files not working

According to this manual of writing files: https://rancher.com/docs/os/v1.x/en/configuration/write-files/#writing-files-in-specific-system-services

RancherOS will create a file and write the contect to it, right?
Nothing happens after reboot the system.
/etc/ntp.conf: No such file or directory

Should I put something else into Cloud-config?