To cite a video in APA format, use the following guidelines. 

• Author, A.A. [Screen name]. (year, month day). Title of Video. [Video file]. Retrieved from http://xxxxx

​Sometimes there will not be an author but just a screen name, and that's fine. In this  case do not put the screen name in brackets but instead use that as the author.

• Screen name. (year, month day). Title of Video. [Video file]. Retrieved from http://xxxxx

Video file is left as is. It doesn't not need to say if its a MP4 or another media type.

The URL can vary and depend on the source.  You may want to check with your professor if you should use the Blackboard URL or a more accessible link.