New chains come separated. You have to use a master link or a press on fitting. It's not rocket science, but you can screw it up. It's extremely difficult to squeeze the links together enough to get the master link to snap on. Some people grind a tiny bit off the thickness to aid in getting it on right. I do not recommend doing that. After you get the master link snapped on, it's a good idea to spread the links back out. The ones you were squeezing to get the master link on.
You may be able to buy a solid chain with the correct links, but I don't know anything about that. Every chain I've bought was too long & I had to remove the correct number of links & install a master link.
Heart of Dixie