Hi,
Not sure about the specifics on your boat but I would expect a reverse bucket - basically a scoop that drops down over your jet outlet.
Usually all the way down for reverse and midway down for neutral.
You never actually disengage the drive, just balance the thrust.
It should be very obvious to see if you have one and you would probably have a leaver to operate it, although modern jet skis are controlled electronically from a handlebar lever.
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