Fuel leaking

[Hardly_Davidson]

First post from me on here and need info quick.

I have a 2017 gy6 150cc something-or-other. There is a screw on the bottom clutch side that is missing and loosing fuel whenever it runs (no more than a minute of run time.) I'm wondering what this is and/or called so I can get a new one. Not sure what system it's used for (fuel system is my first guess; maybe for vacuum?). I wont have any pics until tomorrow because I left my bike at work. Any help would be appreciated