Appearance of a modal window at each call?

Question

HTML

An alcoholic site and you need to notify the user about the topic of the site every time you visit (user age limit 18+). The logic is this: when entering the site for the first time, the user closes the pop-up window, uses it, closes the tab with the site, re-enters and shows the window again.
what I dug up www.cyberforum.ru/javascript/thread780429.html

Answer 1

Recently saw, I can not find a link to the question. The point was something like this

if (!sessionStorage.isVisited) {
  doSomething();
  sessionStorage.isVisited = true;
}

Answer 2

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