Looking to create an asset for the Unity Asset store in C#.

I don't want to give away the source code, yet I want users to be able to purchase + download my work and use it in their projects.

I'm not sure what this is called or how to do it.

Any ideas? Much appreciated!

Software has to be compiled to binary to stop people stealing the source code. DRM (Digital Rights Management) may require a key or an expiry date to manage it.