This video is only for an educational purpose not for any illegal actions
To learn SSI(Server Side Includes):-
https://www.w3.org/Jigsaw/Doc/User/SSI.html
The command is in the below link I cant write here because
the youtube doesn't allow angle brackets
so visit these link for cmd:-
http://gokultechweb.5gbfree.com/SSI cmds/SSI cmd.html