Small black cap fell out of reservoir. Where does it go?

I might be able to figure it out if I had my hands on the machine. However, the other option is a parts breakdown that might be available on an appliance parts website. You would have to search for [your model #] parts then see if they have the breakdown.

Same thing happened to me just a few minutes ago. It’s a cap for the screws on the front right and left. If you look closely, one side should have exposed screw.