Rhino custom command not show in command menu

I am using rhino 6 for developing custom command in rhino. I am following videos but at the end i cannot found custome Name commad in rhino command.please help me to understand what I am missing.

You need to create a RUI file to add an entry to the menu. A custom command from a plug-in is only available from the command-line. If you don’t see the command name in the command-line, then ensure that the plug-in is actually loaded. The first time you load the plug-in the commands are known to Rhino. Loading the the plug-in can be accomplished by dragging the plugin file (RHP extension) onto a running instance of Rhino.