It should come out watery and transparent so you won’t even know it’s coming out if you don’t pay attention, so pay very close attention or risk getting glue everywhere.
What you need now is a toothpick, so if anything gets glued, it’s the toothpick and not your fingers.
Now, apply a tiny bit of glue to the crack, and use the toothpick to spread it out evenly. If you don’t abuse your nails a lot like I do, then a thin layer should be fine to keep it together until you want to trim it out next. Hold it there for at least 20 seconds to make sure there are no air bubbles or weaknesses.
After it dries, you should be able to use a buffer to even out the roughness the glue has caused on the surface of the nail. Then you can paint over it and it should be as invisible as an invisible thing. All done!