Basically you would keep your fingers still and bend them straight while hovering over the keys, pressing keys with the top middle of bottom or tip of each finger. I haven't tried this out other than brief tests on my Macbook keyboard, it doesn't work well on staggered keyboards but might on ortholinear ones. Ideally, with enough practice it would feel fine to type lots of keys very fast and hopefully achieve a high WPM with less errors than regular touch typing as the result of reduced finger movement.
I did some looking up to see if such keyboards exist but didn't find anything other than the the Lynxware CAT
https://www.lynxware.org/ (look at photos on the page). I also looked at the Azeron Cyborg which also uses minimal finger movements, though you have to insert your fingers in each slot.
