Need pivot pin or locking piece to keep ni-fold door fixed

We inherited a bifold door with all the wrong hardware. I found your item 23-214 2-wheeled roller and it works perfectly with the track. What I didn't order was the additional part needed to hold the fixed end of the bifold door in place. Standard hardware stores only carry something too narrow (see picture of sad horizontal wheel that chronically falls out, and other pic of our temporary fix to hold pivot point "in place".

What additional items do I need to order to fit this track and hold the fixed side of the bifold door in place?

Thank you!