This guide will show you how to disable the NTP service chronyd.
The following command will stop chrony and prevent it from running at boot:
systemctl disable --now chronyd
If you'd only like to stop the service, but want it to continue to start automatically on boot, run:
systemctl stop chronyd
While this command will prevent it from starting on boot:
systemctl disable chronyd
The official documentation on stopping and disabling chrony can be found below: