How to run PHPUnit test in openServer?

Question

PHPUnit

Hello! I can't figure out how to connect PHPUnit to openServer. From what I read in the documentation, I concluded that PHPUnit has been bundled with PHP since version 5. I am using 7th.
Wrote a function test. Made a class, in general, everything is according to the rules. But suddenly in the book I ran into this line:

To execute a test, it is enough to specify the name of the file in which its code is saved as a parameter of the PHPUnit program launched for execution from the command line:
phpunit.phar RestaurantCheckTest.php

Here questions immediately arise:
1. In which command line to enter these commands
2. How do I understand that I have it?
3. Why can't you download that mystical archive on the phpUnit website?
How can I run this test?
Thanks in advance!