How to license closed proprietary software?

Question

Licenses for software and other works

Hello
Wrote an application. There was a question about licensing.
How to license closed proprietary software?
Should I add EULA? Or am I not understanding something?
The code is closed, everything is written by hand.
Write a license from scratch yourself?
The program contains a server and a client. Free use is possible only with one client. More than one client - buy a license.
Thanks

Answer 1

What are you to this closed proprietary software? The author, the owner of the exclusive right?