As far a I can see from your photo
does not have the groove below the "teeth" of the drive that is needed for the lock plate on the handle to turn in and thereby catch under the teeth in the socket to prevent than handle from being lifted out.
There is absolutely NO need for the handle to lock in the winch. I myself prefer that it doesn't! A handle "locked in" is just a nuisance in my book. I like having a loop of light line on the grip of the handle so I can slip my hand through that loop to keep it secured to my wrist. Some handles have a hole through the grip specifically to accommodate such a wrist strap.
I'm a cruising man, so for long periods I don't need to use a winch, and therefore I don't need to use a handle. When not in active use my handle lives in a handle pocket in my cockpit
. It is along sheath, sort of thing, mounted vertically, and for the handle to fall out by accident
you'd have to turn the boat
You are a novice
, so you will serve yourself well if you learn the basics working with basic gear
- the simpler the better - while you find your sea legs. Don't look for "science" where science only gets in the way of learning
. And harking back to other questions you've asked, don't let people turn a firehose on you when all you need, and can swallow, is just a little sip of water