Good job Sir. Not my cup of tea, yet it's nice to see you were able to quickly fabricate something that is simple and works for your needs.
I believe it is secured by a bolt through the lug hole.Can’t tell from the photos but for your own safety tie that tire down with a ratchet strap. God forbid but in a accident that spare will kill you. You did a great job fabricating but it needs to be secured so I won’t hurt you or your passengers.