Photo negative of layers?

is there an option to export a photonegative of board layers at export. i’m using my laser engraver to etch my boards and i need a negative version of my board layers. is there any settings for this?

Indirectly. One way I would try: Use gerber export (File → Export → For Production → Extended Gerber). Then load the file(s) in gerbv, which has the ability to invert it.

Or maybe the production pdf export is already what you want. In this image, the white areas are what the laser would have to remove:

Gerbv is that a software? for viewing gerber files?