Think this through.
The gas needs a spark to lighti it.
The gas comes out of a burner. There may also be a pilot burner
There is probably an electrode close to the burner or pilot light.
It needs to stand heat so wont be plastic, probably white ceramic.
The wire will feed this electrode somehow. It may have simply fallen off.
There may already be a wire there, in which case you clould trace this back and find where it should join the ignier lead
Kkejrnhr, June 2018