Polygon Collider 2D doesn't have the "edit collider" button avaliable.

The collider is created on a grid, I have successfully created box colliders, but, as the picture bellow shows, the polygon collider doesn't have the button to allow editing with a mouse, the full inspector window is shown, but if you need more information about the project please ask.

Inspector screenshot : https://imgur.com/a/Xs83ESH