replaced the thermal fuse and the thermostat but not heating up

Jason Timmons we would need to know the exact model number. Since you already changed the most common parts, go ahead and check the actual heating element to see if that works. You can take resistance check for the heater across the terminals of the heater. On my unit the lower safety thermostat was placed on one of the terminals of the heaters. broken heating element should read as open or extremely high. Most should read below 5 to 10 ohms usually, but this will depend on your dryer. Of course you already checked the airflow by checking that the vent is clean and free of obstruction as well as the fuses to your dryer. There should be two fuses for the dryer in your fuse panel if you are in north America and running on 110V to give you the needed 220V

If it is not the thermal fuse, thermostats or heating element it is probably the heat relay . look at the Control board visible scorched or damaged points on the back.