How to capture a video from a web site
with the right click of the mouse button and the option "view page source" ?

It's always individual. Some web sites don't allow downloading, blocking this option in their code. Video capturing is done by software, though I'm not a specialist in it.

But how can I find this link with video in wall of text ?
There is a way?

Tried to help in a private message, but no luck..

Case 1: html video tag

https://skr.sh/s691SJ1N0rE
https://www.redbull.com/int-en/

Press F12, and find <video> element, there is attribute src with a link - https://cs.liiift.io/v1/RBMN/pd/2/6D/J2/XY/...DJ2XYDWBH11.mp4
It can be opened in browser, or be downloaded by smth like DownloadMaster

Case 2: youtube video

Install DownloadMaster latest version.
Open video on youtube site, if its embed.
Copy its URL and paste it under "+" sign in downlaod master (in browser press ctrl+L -> ctrl+C -> go to DownloadMaster -> press Insert)

Case 3: embed vimeo video, VK, OK, instagram, twitter and etc. - google how to download video from these services.

Hmmm...
could you try with this?
view-source:https://vider.info/vid/+fxxx1vx

Link is not opens, 404 for https://vider.info/

and now?
https://vider.info/static/player/v58/player...eo/222692/v.mp4

Nope, only favicon is loaded (status 200), https://vider.info still 404 by this link.
And I get 403 for https://vider.info/static