It has a bevelled head set and one chainring.
The Serial number is OB210122878. The first digit I think is 0, it's got a slash through it but is different than the obvious B and 8 found in the serial number.
From the first 4 photos, this is a 1-by mountain bike with a derailleur-based rear gearset.
I was wrong in the comment, it is not a BMX.
I see an empty rear disk brake mount which also means its not a BMX - they always have rim brakes or a coaster.
There is no fork, and no wheels so you have a bare frame. It won't be a rideable bike without additional parts.
It could be a useful bike, but give it a good wash and look for cracks or damage before buying other parts.
The head tube is not "bevelled" - instead I'd call it barrel-shaped and probably hydroformed or made in a press. This allows the frame maker to use a wider tube for the head tube, and provides a wider place for the down/top tube welds. This will add strength and stiffness at the cost of weight. Not really an advantage because the headset bearings are still relatively small; this is a cost-saving design.
As for identification, it looks like a common east-asian frame made in bulk and has no specific redeeming features. If you like it, by all means ride it. This is not a valuable museum piece.
There's nothing wrong with you hand-lettering "HUFFTY" on the side, or get a couple of decals cut out to say the same. After all the work you'll be doing, it may as well be named for its owner+rider.
If you do assemble this bike to a rideable state, please do post a photo and describe how you got on.
