4 whell drive not working nothing happen while move  the 2-4 whel drive help please

[2015 Z Force 800 53/Trail EPS]

Check the fuses first, then check if the actuator is working when hitting the switch. If it is, then I would look at the slide inside as it's plastic and strips easly. If not working I would look to the switch and any related relay.

Had the same issue a while back and it turned out to be the very little dc motor that engages and disengages the 4wd.  Replace the motor inside the assembly and all was back to normal.  Had a somewhat difficult time finding a dc motor that would fit, but at the end it was a cheap and easy fix.

Check this video where you can see the little dc motor inside of the assembly.  That was the only thing I replaced.
https://www.youtube.com/watch?v=raCNbin-i64

This is if you want to replace the entire thing
https://www.youtube.com/watch?v=HL-JW__NprU

I had the same problem on my 500. Fortunately, just removing this relay and reseating it resolved my issue.