Go to an auto store and buy a cheapie Valve Stem Tool. It looks like a minitaure 4-way tire iron. It has a slotted end that should fit into the valve stem. Then turn to tighten. Be gentle, low torque, just a little turn clockwise.
Slime/4 way tire valve tool (2044-A) | Tire Valve Stem Core Remover Tool | AutoZone.com
If you turn counterclockwise, you will take the valve stem off, that's fine if you want to take it off but make sure you hold on tight to it or it will hit you in the eye when all the air rushes behind hit and pushes it out. Also, if you take it off to replace it, you may run into an issue with the TPMS sensor. So try tightening first. Failing that, maybe the LamboStuff guys have a valve stem and TPMS kit for you.