I don´t have download of video from this site https://www.alfaconcursos.com.br/?_ga=1.75550039.33613316.1464975875

Hello, this site is not on the list of supported resources.

The full list can be found here: http://en.savefrom.net

Please, use our extension Video Downloader Pro: http://videodownloaderpro.net
Video Downloader Pro is a magic tool helping you download any media content from any
website all over the Net.

Possibly, it will download from the website you want.