Invention, discovery..does not matter. There was a point in time when humanity was oblivious to the phenomenon and then there was a point when we were not and we could generate and use it.
It is false to claim that there was a moment when electricity went from unknown and opaque to understood and producible. That “moment” was thousands of years and all incremental.
Tell me the date when humanity went from oblivious to electricity to generating and using it.