How to protect C# code from decompilers and how to hack exe?

Question

.NET

Hello, tell me how you can protect your code from all sorts of bad guys who want to hack or break the program.
And also how to pack the program except for UPX, since I myself open everything that is packed with UPX in 5-10 minutes.
Are there any more worthy analogues from free ones and is it possible to pack the packed exe-file again, only secondly with some kind of packer ??

Answer 1

everything is decoded... the question is whether your product is needed...
Prepare unique builds for each client of your application before selling and require before installing a copy of the Client's identification data input with verification on the server.