Valve cover leaking oil

[PANDEMIC]

so it looks like my valve cover is leaking oil. not sure if it is the valve cover gasket or the screw that is on the very top towards the carb. it looks to have some kind of washer and oil is up in the washer area. is that some kind of pressure screw? I tried to remove the 3 bolts holding the cover down but something is holding tight like a good seal on the gasket. the rhino did make a deer tuffff sound and I seen oil down there buy the valve cover. it looks like the head gasket area is dry oil is up top. and clue ???

and what is the screw at the top of the valve cover for