Dryerwont stop

I have a Maytag dryer, MDET446AYW, that won’t stop. That means, it heats up, the cycle advances, everything works fine except it just doesn’t stop.

The timer does work fine, meaning that if you set if for 20 min, for example, it advances and stops. This would seem to point to something in the moisture sensor, but what? I have seen some things online that say it needs to be clean, but I am not even sure where it is.

Thanks for any advice,

John