❔ C# app on Linux

Hello , I'm trying to create a C# app on Linux but I think it's just not possible. I tried multiple methods to do that but none of the work. What do you think? My las hope is to run an emulator for windows on my linux, but whenever I try to open my virtualbox Linux, the system is crashing or lagging. What should I do? (I can't move on windows and I can't use other alternatives! )