Two things. One, the error message is giving you a rather large hint about what's wrong.
Taking a look at the documentation on ResXResourceWriter,
here[
^], will tell you exactly what you're missing.
It says that you need to import the System.Resources namespace, which is found in the System.Windows.Forms assembly.
Normally, in a Windows Forms app, you don't have to set a reference to the assembly because it's already there automatically. But, since you're writing a Console application, you have to explicitly add a Reference to the System.Windows.Forms assembly. After that you simply add the line "using System.Resources" to the top of your code file.