How do I actually use this??

I am so lost on this addon. I created another post type…mobile businesses that do not require physical addresses. But now I have no idea how I am supposed to make it so that users can have one form to add a listing and have the option to choose between the 2 options: a brick and mortar business listing and a mobile business listing, and then fill out the respective form from there…

I see something on the CPT documentation about this:
“To Link one CPT to another, visit the Custom Post Type Settings Custom Fields tab.”
and then:
“CPT link fields are near the bottom of the page. Choose a link type and click to add to your CPT listing form.”

I suspect what I want to do has something to do with this…and I found these fields…but nothing happens when I add them, so I think I must be doing something wrong.

The documentation here is REALLY unclear to me. I am getting really frustrated, in fact, at this point, I am realizing that there really is SO much of the documentation which is really unclear to me. If only the documentation was a LOT more clear and fleshed out, I could spend SO MUCH LESS TIME coming to the forums asking for people to help me understand things. SIGH.

Don’t get me wrong…the tech support on these forums is SUPERB! You guys are so kind and patient and helpful every time! I just wish that you could maybe make your documentation more helpful so that I don’t NEED to come to you for what feels like every other step because I’m not understanding your documentation. I really do prefer to figure stuff out on my own and not rely so heavily on others to explain things to me like this…But I’m not even finding lots of tutorials on YouTube or anything like what I’m trying to do so I rely on coming here to ask every single question I have. I would MUCH prefer to have the answers in front of me easy to sort out.

Anyway, I digress…different CPTs…how do we get them onto the same add listing form and allow people to choose the one they need to use?