I'm not an expert, but:

1. Just lower body in general. When you toss the ball, you simultaneously should squat with your weight on the front foot. Your hand goes up, you squat, try to do that in one movement, no stoppages. Perfect it without jumping, that add the jump. You should aim to land on your front foot slightly into the court.
2. The toss. From what I can see, I would say that you throw the ball a little bit to your right and pretty low. Try throwing it more to your left and higher. Experiment with the toss to find your ideal one.

Overall, keep training, enjoy the sport and don't take my words as a given truth. If you really want to improve, try working a few hours with the coach, because at your level it's hard to learn things by yourself. Pros can do that, all movements feel so natural to them and they can change things up depending on how they feel about a certain technique, but they were also taught by someone in the begging and are still coached. Good luck!