Full service stations are a thing of the past. You can't tell if a tire needs air just by looking at it or even by kicking it, because they're not bicycle tires. It is someone's responsibility to check and add air to the tires on a monthly basis.
1. First you have to go to a repair shop or gas station that has a compressed air system with a pressure gauge. You can visit a gas station with air pump at https://buyusedtires.org/air-tires-near-me/ to check the air in your vehicle.
2. The car must be parked so that it can reach all four tires with the air hose.
3. Vehicle tire pressure information must be found. There is a sticker that can be found on the lip of the driver's side door, in the trunk or on the glove box.
4. The plastic cover of the air valve must be opened. It should be put in a pocket so it doesn't get lost.
5. Air pressure should be checked with a personal pressure gauge or air pump at the service station. The pressure gauge must be pressed against the valve and firmly held. If there is a hissing sound, it means there is an air leak. You have to push harder.
6. If necessary, air should be added. The air pump hose must be pressed against the valve while pressing the lever at the end of the hose.
7. Air pressure should be checked with a manometer. Air pump hoses can also be used for inspection.
8. The tire must be deflated if it is accidentally deflated. The small needle in the center of the valve needs to be pushed down to release air. Many tire pressure gauges have a small button for this purpose, but claws or pins can also work.