Where is XQJ and how to add?

I’m using the Gradle Kotlin DSL and trying to add the XQJ library or API:

It’s somewhat arcane, perhaps, so asking here also. As an aside, an XML build file would be awesome. Yes, yes, Ant creates absurdly long build files. And I greatly appreciate the scripting capabilities of Kotlin. But for configuration: Main-Class, compile, run or transitive build requirements, project name, for that type of configuration XML would provide structured clarity for myself, at least.