Unity ll2cpp Game = ECO on steam need help

First off I am sorry for how ignorant in this I am.

Game=Eco.Exe on steam

The game is in unity with ll2cpp so I found a few old tuts about using a dumper when I go through the steps I get this.

Initializing metadata...
Metadata Version: 24.2
Initializing il2cpp file...
Il2Cpp Version: 24.2
Searching...
CodeRegistration : 0
MetadataRegistration : 0
ERROR: Can't use auto mode to process file, try manual mode.
Input CodeRegistration:

So I don't know the codegen registration I read a tutorial that said you had to download unity then build your own empty game with il2cpp and then use IDA to get the codegen from the gameassembly.dll in the build of your empty game and use that. Well I did that and guess what it gave me no gameassembly.dll it gave me assemblycsharp.dll and Pdb. So naturally I tried to open it and it had nothing of what I was looking for in it for this code of course. So I just don't know what to do. I want to learn this so bad its driving me insane. Please help?

Game on steam is Eco I don't want a release I want to know how to do it myself btw this game use to be native cheats with dnspy and the whole shindig now the have upped their gig.

Sigh can someone just give me eco's Gameassembly.pdb at least?