What is the default module type for kotlin/js

https://kotlinlang.org/docs/reference/js-modules.html
and
https://kotlinlang.org/docs/reference/using-gradle.html#attributes-specific-for-js

Say that “Plain” module type is the default.

But this prints “umd”.

compileKotlinJs {
    kotlinOptions {
        println moduleKind
    }
}

https://youtrack.jetbrains.com/issue/KT-36920