Did you mean create them in the editor, or how to activate them?
To create an Outro - Win or Outro - Loose in the editor, you create them the same way you create an Intro by clicking on the small drop down list with 'Mission' currently selected, and choose 'Outro - Win' or 'Outro - Loose'.
To set it up that they activate after a mission, you will use a trigger. Find inside the 3rd section (or toward the middle of a trigger box) where it says "Type". The default should be "None". Click on this. There will be many options. You are interested in "End #1" - "End #6" and "Loose". "End #1" through "End #6" all activate the 'Outro - Win' and "Loose" activates the 'Outro - Loose'.
Hope that helps.