[Amez530]

So I was replacing the valve cover gasket and when I was putting it back on I noticed some piece fell off from under the VC it just looks like a plastic cover of some sort? There’s two of them the other one was still on I can take it off and put it back on but the one that fell off keeps falling off. Anyone know what these are or what they’re called and what their purpose is? Can it be glued back on? Do new ones have to be purchased? Or do I have to buy a whole new VC?