Settings will vary with your camera type and model, but the general idea is-
Use a tripod. Exposures will vary from 1 second to 10 seconds or longer, but to avoid camera shake you need a tripod or to fix the camera solidly on a bean bag or similar.
Use your base ISO. 100 or 200 or lower if you have it. Fireworks are bright.
Start with the smallest aperture the lens allows. f/22 or smaller if you can. Check your first shot and open up if necessary.
Manual mode. Manual focus. Try to focus on the “launch site ” beforehand if you can. It’s probably dark, so try any streetlight or headlight near by as a starting focus point. Once you have found acceptable focus, leave it there.
Use sense:- Get there early, set up where you won’t have kids falling over the tripod. Dress warmly. Have a spare battery. Format your memory card in advance.
Post editing can recover some shadows at the site, but you may prefer to take a shot of the site before it gets dark and do a composite.
Reflections in water add to the height of the image and trees etc lit by fireworks behind them add depth.
Alternatively- especially if no tripod or support is available- try simply using a high ISO , hand held at maybe 1/60th or 1/100th of a second. Any actual firework captured may be burned out to white, but you may also capture some of the crowd activity, illuminated by the fireworks. Use raw and take a lot of shots. There’s a fair chance of getting one or two decent ones and with a raw image there may be a possibility to reclaim some of the burn out. Check your first results and play with the shutter speed, or lower the ISO if possible. Aperture wide open.