Ceiling fan with humidity sensor to trigger a towel warmer

Hi, I have a ceiling fan has a humidity sensor and I would like it to turn on the towel warmer if running longer than 2 mins. I have the towel part done already but I wonder what would be the best way to find out that the fan is running? Most likely it’s wired as a 3 way.

What kind of z-wave switch would you recommend?

I take it the humidity sensor is not connected to ha?

No it’s not. I’m looking for a recommendation on this as well. Would any z-wave 3 way switch work to fulfill my requirements?