why does the patrol heli never spawn?

You skipping night?  Because skipping night can do that.

I have always day on but other servers have it too and it still works do you know why ?

There's a difference between freezing the time and skipping night. The time needs to progress in order to trigger the events. We use this to skip nights and it works nicely with all the events:

https://umod.org/plugins/time-of-day

If your time is frozen, the 'Automated Events' and 'Timed Events' plugins can bring back the patrol helicopter.

what command do i set ? i mean to call heli

You don't need any "command", you use the settings in the .json file for the plugin you're using.