I would like to be able to adjust the max level for a lot of fun.

Yes, there's a config value for it.

Where can i find it?

Called "perkLevelCap"

I'm a little silly. Where to find this parameter. In the config folder, I only have the world generation settings

there's 3 configs, as per forge's config standard:

• <mc directory>/config/<modid>-client.toml - the client config for mods. is only loaded on the client
• <mc directory>/config/<modid>-common.toml - the common config for mods - is loaded for both server and client, but the server doesn't override client configs when joining a server
• for singleplayer servers:
  <mc directory>/saves/<worldname>/serverconfig/<modid>-server.toml
  for setup dedicated server:
  <mc directory>/world/serverconfig/<modid>-server.toml
  the server config. is loaded on the server and gets sent to the client upon joining a server

what you're looking for is AS' server config.

Thank you very much