Why my dryer is not drying the cloth properly

Check for full lint trap.

Check for clogged exhaust, sometimes birds will build a nest in there. You can disconnect exhaust hose from wall and use an electric blower to blow out any debris. Just make sure you have a tight seal so you won't get any back blast.

Try different settings to see if dryer gets hot on different settings, could be a burned out heater coil if it stays cold using the different settings.

Clean dryer sensor if your dryer has one

Make sure you are not filling it too full. Also, put like clothes together, (light weight fabrics together and heavy fabrics together)