Configure Videojs to use the local library Videojs in Drupal 8 gives the following error:


  Missing the Video.js library. Please download Video.js and extract it into the //vjs.zencdn.net/5.0 directory.


How can I configure Videojs to use local files? Where should I put Videojs files?

I think Videojs has not configuration interface.
The README.md included with the downloaded module says:


  
  Download the Video.js library from http://videojs.com. Extract the module to sites/all/libraries/video-js and make sure that sites/all/libraries/video-js/video.js exists. NOTE: you can skip this step and use the Video.js version from the Video.js Content Delivery Network (CDN).
  


A comment in the documentation block in the module file suggests that the Libraries API determines where to places libraries.


  Defaults to videojs_directory when using the local file path location
  or whatever location the Libraries API determines.


This location is also set by the videojs_directory configuration variable, which could be set by importing a YAML file via Configuration Management interface or with a tool such as Drush or Drupal Console despite the Video.JS module not having a specific configuration page.