I should have another box below the one circled. The box I need has a plus and minus sign next to it. Searched high and low for the setting but no joy!
I opened the Editor Type in top left of window to the File Browser window. I located my desktop folder and set up a New Folder here. In the instructional video I watched he then enters a further piece of text in the box below the file name box. The text he enters ends in an underscore like this _. I believe its called a partial. I can't do this as there's no box in which to input this text