Many members over the years have just fitted the space saver spare without the bracket. It’s a tight fit in the hole so no real need to lock it in place .
Pull the half circle foam trim out the boot and see how the wheel fits, try it both ways around .
when I fitted mine i cut a cardboard template the same size as the grey boot mat, then cut away the cardboard until it fitted flat in the boot around the spare.
Then laid the cardboard template over the grey boot mat, and cut it with a jigsaw.