Custom Cookie in Selenium

[HackerMad]

How do I put a custom cookie on a website and it injects the cookie into the website. I do know the elements :GetCookies and SetCookies exist. If they do the same thing I want please teach me how to use it, i read the sentence at the bottom but didnt understand it.

[qMMMp]

call the page
then inject cookie
final, refresh page

[HackerMad]

i used javascript thanks