Scrape out the old rope gasket, buy matching size gasket material. Glue in new rope gasket.
You can use the thin, watery, difficult to use gasket cement sold where you buy the rope gasket.
Or go to an auto supply store, and buy Permatex 'Ultra Black' RTV gasket sealer.. this wonderful stuff will do the job with much less mess
and fewer cuss words.
Do NOT stretch the rope to fit. Install the rope gasket with no stretching or tension on the material.
Use a piece of plastic, like a loaf of bread bag, or a garbage bag or the plastic grocery bags.. slip the bag over the door, covering all the new rope gasket and gently close the door against the stove, DO NOT close it tight, just close it enough to hold the rope in place. or you can tape the plastic to the stove front, then close the door against the stove..
The plastic will keep you from gluing the door shut from excess glue. or gluing the rope gasket to the stove instead of the door.