Label associations in UML diagrams

I would like to add labels to the associations that IntelliJ (Ultimate 2017.2) creates for UML diagrams. The class diagrams don't help me much unless I can add a name or label to the associations.

Have a look at this web page: https://www.uml-diagrams.org/association.html.  Both ends of the association have names ("author" and "textbook"). The association itself has a name in the middle of the association line ("Wrote"). I need that capability.

I hoped I could edit the  .uml file that is created when the diagram is saved. I thought there might an element or attribute that controlled names on edges, but I did not see anything like that.

How do other users work around this limitation? Do you do your modeling in another tool or is there a way to generate richer diagrams with IntelliJ?