How do I adjust my bifold door to keep the roller coming out

To adjust a bi-fold door, you would turn the screw at the bottom pivot corner to raise and lower the door. The top of the adjusting screw seems to be broken on yours so that won't be possible.

We have and adjusting pivot we believe would fit in the black plastic housing. See our 23-116. The diameter of the stem is 7/16" and length is 1-9/16". To adjust ours, you use wrench to loosen the nut to unwind the threaded pin and then tighten the nut.