The "Copy to Clipboard" button is located on the "System Info" popup, which is displayed when you press the "System Info" button within the "Info" dialog. The "Info" dialog is opened using the "i" button of the editor's toolbar.

Activating the "Copy to Clipboard" button will place information about your system and your edit-on Pro configuration on the clipboard. It can then be pasted to any other application, e.g. notepad.