How do I connect the link rod from the door handle to the latch?

Without seeing inside your door, here is what I suspect. The rod which attaches to the handle (outside) has grooves on the bottom end. It looks like a screw thread, but it is not. It attaches to another rod via a plastic clip, used for adjustment. Check the bottom of the door and see if it fell off. At any rate, there should be a video on the net to guide you.