How to use cookies correctly?

Question

PHP

I use a "headless browser", I need it to work like a normal browser, so besides simple page navigation and clicking on buttons, I think to use cookies, there is a function for taking current cookies and there is a function for setting cookies, the question is when should they be used?
Go to the main page to take cookies and then insert them when you go to another page, or set at the beginning and take at the end of the work, how should they work so that it completely imitates the browser?

Answer 1

usually cookies are transmitted by the browser to the server before each page request. if you are interested in more details, there are traffic analyzer programs