Log user out after closing website

-- url of the page with the problem -- : s293983206.websitehome.co.uk/elevateshop...Full_Package%281%29/
-- Browser(s) name and version -- : Firefox - latest

I've been doing the final tests for my clients website and have noticed that when I close the hikashop website and then go back onto it either by clicking the back button on the browser or opening a new tab and inputting the url to the website, it leaves the user still logged in.

I have set the sessions and cookies to 0 under the Joomla configuration, but it does not solve the issue.

Is there any way I can log the user out automatically when they close the website?

Thanks in advance.

There is no way because websites cannot do that.
The way it works is: you enter a session timeout in the joomla configuration, and if the users doesn't display a page during that interval, he gets logged out.