From the two photos you’ve posted, it looks like there’s a little bit of the grooves left in the top of the screw, but not enough for your screwdriver to grip.
Try the rubber band trick first, mainly because it doesn’t cost you anything other than a rubber band to try. The combination of the little bits of the grooves and the grip from the band might do it.
If it doesn’t, a sacrificial screwdriver might work. You basically need to file off the pointy tip of the screwdriver until it can reach what’s left of the grooves, and unscrew it with a bit of downward pressure.