If you’re far away from it, you’re probably going to want to zoom in as much as possible. Don’t. While zooming can help you see the distant object better, it often comes out blurry.
Instead, try to go as close as possible to the fireworks with your feet. And, if you’re still far away, don’t worry. I guarantee that if you take a large quantity (as mentioned earlier), you’ll still manage to find a few that work for you.