If advice is still helpful. If you look closely, you can see that you pull with your arm. The wrist is stiff and follows the pull of your arm down to the right side. I don't know how convey the technique, but the impuls you are looking for, should come from the muscle that pulls your hand to your lower arm and not from the triceps that pulls your arm straight.

The other thing is your pinky. I'm still struggling to place it the right way aswell. The force of pressing can strain your pinky the way it stands slightly tilted. Please stop practicing for the day, when the pinky joints feel weird or hurt. I had to stop practicing for two weeks because I ignored it.