1) Make sure editing is on for the class. Click 'Add an activity or resource.' on a chose section.
2) Choose H5P.
3) Use the search tool to look up 'Interactive Video' then double click the area highlighted in the image on the right by a red box.
It's worthy of note at this point, that after you choose a type of H5P object that you want to use, most of them have in-built tutorials and examples which you can access via these symbols;