How to connect toilet flush valve chain with provided v-shaped connector
(caveat: I've never met this version in person...)
That appears to be intended for the &quot;between-beads&quot; part of the chain to slide down into the smallest part of the tip. The beads should be larger than the opening in the smallest part of the tip. Depending on maufacturing tolerances, it may take some force to get the chain in there, or it may not. If loose, the chain should stay put by gravity, as both sides of the chain should hang down. If you have to force it in, then it should stay put until pulled out.
If the beads are smaller than the narrowest part of the slot, I might be wrong.