Using a smart trainer in dumb mode

This may seem an odd question for Zwift (perhaps better on Wahoo) but here goes nothin’. As a newbie, I am enjoying the Zwift sessions but might want to ride my trainer while watching a movie or TV from time to time - setting the resistance my self and/or changing it up with gear-shifts and effort. I am using Apple TV to Zwift, so obviously can’t be in Zwift while watching a movie (and even if I concurrently ran Zwift on my iPhone or tablet, I imagine that it would be pretty distracting).

What I would like to know is whether smart trainers can be used on occasion without a cycling app. 20 years ago I had a basic Tacx trainer which I could use for that sort of purpose but don’t know how I would do so with my Kickr Core.