There are better ways. Post a photo of the coin so we might guess the nature of the green and suggest a next step. Some types of green protect the coin and must never be disturbed. Other types will destroy the coin in time.
It actually doesnt have any green corrosion on it yet it just has a black patina i was worried it may change
Click upload file and select the image. It’s it’s too big use MSPaint or Picresize to make it smaller
That patina looks stable. I don't see any reason to put anything on the coin. It's attractive as-is. The overwhelming majority of ancient coins don't need any conservation or any applied materials, except those with active cases of corrosion. Unless you live under the sea in salt water, then you'll be fine. Nice coin btw.
