Your wheel is obviously leaking somewhere.
There are a few places that you can have a leak related to the wheel
The Schrader Valve - The schrader valve within the valve stem where you refill the air can be bad and require replacement.
The valve stem - The valve stem where the schrader valve is in can have a bad a seal on the rim
Tire Pressure Sensor - I didn't look up if you have one but many cars do have a tire pressure sensor. You can have a bad seal on your wheel.
Tire Bead - All around your tire where the inside diameter of it meets your wheel requires a nice smooth surface. You can have leaks here.
Overall
Any damage to the surface of any of the above points can cause a leak. It could have been a tire change from long ago from a careless tire changerworker. A good scratch along the bead, a pair of pliers replacing the valve stem and a nick in the valve stem hole.
You may need a new rim but you would have to pull the wheel and remove the tire, valve stem and pressure sensor to give it a good inspection to determine where the leak is and see if you can fix it with some sandpaper if it's a bur on a sealing surface of your wheel.