Thank you a lot for the explanation and providing this article, I'l read more about OOP for sure

It's not like it's better to use "static". You use static keyword when you want to call method or variable without creating class instantiation. In this example I just want to call method so I skipped creation of new Kata object. I suggest you read some about object oriented programmin, you will fully understand purpose of this keyword 😇 Anyway there is cool article about "static" keyword:
https://www.baeldung.com/java-static

is it better practice to have static keyword in it?

It do not work to BIG letters

Nice code, I liked it. (&& - do not need)