org.openjfx:javafx-fxml:11 is empty module

[Ashley Bye]

I'm trying to import the JavaFX FXML module into a project in IntelliJ.
However, none of the expected classes, e.g. FXMLLoader, are available. When
I look in the external library, the javafx-fxml dependency is empty except
for the MANIFEST.MF in META-INF. I'm either depending on the wrong thing or
there is a problem, but since I can't find any other reference to this
problem, I suspect it's me. Any help would be appreciated.

Ashley