Hi, I'm trying to add an addon that changes terrain generation, but for some reason it doesn't work, I've only tested it so far and I'm convinced that no addon will work

Do addons need to be inside the world folder or just being outside is enough?

And how can I regenerate the world? I looked for this option and didn't find it, so I created a world in my Minecraft and uploaded it but it didn't regenerate

HELPP

é só ir em reinstall e clicar em reintall, mas como mundo vai "resetar" ( não tem como colocar um mod que altera a geração de terreno se o terreno já foi GERADO?)