You can embed video in all three types of Instructables: Step by Step, Photo, and Video.
For Step By Step and Photo Instructables:
-In these types of Instructables you will need to embed your video directly into the editor. Find the embed video icon at the top of the editor it looks like a strip of film (see figure 3)
-Clicking on the embed video icon will open another window with the prompt "Paste Embed Code Here" (figure 4)
-Go you your video and find the "Share" or "Embed" button (figures 5 and 7)
-Copy the embed code, it should start and end with "iframe""iframe" (figures 6 and 8), include the surrounding brackets