I tried making the firework behavior.

I don’t want to port it to a datapack and it’s too big to fit in a URI and so import this JSON to Blockcase

https://reddstrider.github.io/blockcase/

Press copy command, put it in a command block and power it.

You’ll have to power the rail, then break the bottommost minecarts one at a time for the full thing to load, and the impulse command will need to be disabled, then repowered.

I’ll fix all these issues when I return to Blockcase maybe.

Here’s that JSON I was talking ‘bout:

https://reddstrider.github.io/tumble_firework_cannon.json

Once done; to give yourself a firework launcher you can run this command

give @s warped_fungus_on_a_stick{display:{Name:'{"text":"Firework Cannon","color":"red","bold":true,"italic":false}'},Unbreakable:1b,fireworkShooter:1b} 1