Filament Spool Bearing Bracket question

Does anyone have pics of how everything goes together? I don't understand how it mounts to the bar using the T-nuts.
I added a standoff washer between the spool/bearing and the mount. I've attached the stl for the bearing here, along with a sketch of the assembly. I didn't use t-nuts because we had 8/20 bolts and hardware laying around for mounting it to the bar.