A zipper without a stopper can be a real problem. Perhaps you pulled too hard, and the stopper broke. Another situation in which lightning could disperse - it had to be shortened. This method will help to collect the two halves in the dog. You come to the aid of an ordinary kitchen fork.
Secure the plug to the desktop with something heavy on top. Put the dog on the center teeth.
Now you need to put two ends of the zipper in the dog. Push them up at the same time.
Pull the ends of the zipper toward you until it is fully fastened.
It remains to make a new stopper. You can, for example, sew up painting with a thick thread. Done!