I just got done with this process recently with good results. I brought the receipt which was a digital screenshot of what I paid printed out, as well as a "manufacturers certificate of origin" for the brand of canoe I had. I called their customer service and they told me to print one off their website and write the hull number on it.
I also filled out a title application just in case, but since the canoe was under 16ft I didn't actually need that, but your milage may vary. Make sure you bring plenty of ID/documentation, having extra stuff is better than getting turned away for not having what you need. It was brutal when I was there, people were getting turned away left and right lol.
check out this site -
https://www.dmv.org/nj-new-jersey/boat-registration.php - lots of information there.
Good luck, its worth it in the end! Took mine out with the trolling motor this past weekend
