The server that I'm making doesn't allow including Subtle Effects. I would suggest making it a client mod, with only other people with it installed being able to see your particles.

if you're using Forge 1.20.1 then there's not much I can do, because it's a bad loader and doesn't allow that. Otherwise, did you read the description or FAQ? they say the mod works just fine client only. Installing it on the server is optional, but CurseForge doesn't give me the option to specify that its optional.