Drying is taking too long

Need you advice to fix the problem in cloth dryer.
Dryer is working but clothes are taking too long to dry.
I cleaned the vents
what else needs to be done?
Do I need to change heating burner etc. I guess the dryer probably does not have heating elements because it is a gas dryer
Any advise:mad:

Hi,

Take the dryer apart and clean the housing around the blower.