Hello. Does anyone know if there is an application for linux, to obfuscate the plugins code? .cs plugins.

C# is a very open language, so the closest you can do is partial obfuscation (plugin basics such as hook names can't be) or minificaton with plugins where code is directly available. Both of those are easily undoable though. Google has a few solutions for both of those.

Simple thing - if you are asking that questions, that already means you don't need it. In theory nobody needs your plugins. People who installing leaked plugins never will buy it from you, so that doesnt makes much effort