(Pre) player login event

I'm reposting this because for some reason a moderator closed it for supporting piracy, even though it has nothing to do with that.
Me and all my friends own the game legitimately, and I am just asking how I would go about making a mod that allows a certain offline-mode name to enter the server, as a troll.

If I wanted to support piracy the server would be online-mode false. But I don't that's not what I want.

BY "premium" I mean legitimately bought game, and by cracked, i mean using an offline mode account.

Once again, me and all the people playing on this server have legitimate minecraft accounts.

Hello guys, 

I am making a small troll mod for 1.16.4 to troll my friends with.

We play a modpack of around 15 mods, and there is no server software at the moment for 1.16.4 which supports both spigot and forge.

So, I am going to write a small mod instead of a plugin (which I have more experience doing).

I was wondering which event decides whether or not to kick the player that is joining when they have a cracked account.

The server is premium, and I want to login with a cracked account in order to troll them. The problem is, I'm not sure which event decides if the player is cracked.

Does anyone know an event for this, or a possible workaround?

Thank you in advance.

Edited April 2, 20214 yr by ajGeneric