Can e2e test cases in Katalon be written in Javascript language

As far as I understand, Katalon (https://www.katalon.com/ - a tool for e2e testing) can record your actions and make test case scripts out of them (which use Selenium).

You can also write your own test case scripts directly in a programming language.

I'm wondering if the language in which test case scripts are written is only Java, or any other language (Javascript in particular) can be used?