This is another rather difficult lesson that will help you learn touch typing. You will practice your middle and ring finger for the keyboard row of keys above the base row.
When you keep your index fingers on the reference keys (let's remind you that those that have insets) and you move your middle finger upwards, your finger should naturally move to one of the two keys for the given hand that this lesson applies to. The same will happen with the ring finger. That is why it is so important to keep your fingers correctly positioned in the base position. When the hands are not correctly positioned at the beginning, or the index fingers do not touch the reference keys, then it becomes necessary to look at the keyboard. Of course, if someone is well aquainted with correctly keyboard typing, they can hold their hands in any position and still type without making errors.
After all these years, my hands are still wandering on the keys with insets. It gives me a sense of confidence in writing fast. I always look for keyboard keys with insets when arranging my hands for typing. If it occurred to you that these keys are for beginner adepts trying to master fast typing, give up that thought. The keyboard you use has been a source of evolution for over a hundred years since the typewriter was invented.
This touch typing lesson will not be the easiest, so focus, relax your hands. Most importantly, don't forget that learning to type without looking at the keyboard should be a pleasure.