Running hot

change or test the thermostat in a pan of hot/boiling water and a thermometer , if the coolant looks crappy flush the system

You likely have a coolant leak. The leak needs to be found and repaired.

Top off system with coolant and use a pressure tester to find your leak. If you do not see or hear a leak but the psi is dropping, you could have an internal leak. (Head gasket).

Guru9FSV8, you are way over their head. "Something is leaking from under my car" tells me this person has very limited knowledge about vehicles. No offense intended.

It’s the heater core leaking