If you want more pop, change your racket to something around Mid or mid+ sizing. It will allow you to swing much faster.
You're kinda going thru the motions in your vid. Stop, set, load, and then go into your motion.
Swing faster. Your swing speed seems really slow.
You seem tall enough to hit flat first serves. Learn them. And learn a true second serve, which takes about 25mph off the speed of your first serves, but the spin makes the ball go IN every single time.
Learn specific serves. Like slices towards your left corner, flats up the middle to handcuff the returner, and twists out far right corner.
Then learn to hit each serve to at least 2 of the 3 quadrants of your opponent's court, both first serves and second serves.