How to send a shell command to another server using PHP?

Question

linux

I have a server running a PHP script script
, I need this script to send a direct command to the console of another machine (Like an SSH terminal)
and return the response it reported.
How to implement?
What could be the difficulties?
Let me read something on this topic?

Answer 1

https://www.google.ru/url?sa=t&rct=j&q=&esrc=s&sou...

Answer 2

On the 1st server - create a request to the 2nd server (wget, CURL).
And on the 2nd, in the method that receives the request, execute exec ().