What address should be specified as "Web Server root URL" in PHPStorm when working with Open Server?

Question

PHP

I apologize for the banal newbie question. Couldn't find any info unfortunately, and the Open Server forum hasn't been sending a valid email for a couple of hours to ask a question on their forum.
In PHPStorm, I set up a new project based on the existing files and folders of the site, which are located on the Open Server along the path: C:\OpenServer\domains\mysite.ru. I specified this path as Project Root Directory. Next, you need to specify "Web Server root URL":

What exactly should be specified here? I have about 5 websites in my domains folder. The server is running; sites on their domains open (the hosts file is overwritten normally). mysite.ru - opens perfectly. But like this if you specify in the browser:
localhost/mysite.ru
localhost/domains/mysite.ru
localhost/domains/mysite.ru/www/index.html
- Gives a 404 error.
So what is the "Web Server root URL" in this case?
Thanks in advance for your reply.

Answer 1

It specifies the URL by which you open the site in the browser.