Sorry to say, but the experience to import bookmarks is not exactly smooth nor obvious.
Yes, importing is mentioned in the add-ons' page, but it doesn't say how it's done at all. The contextual menu from right-clicking on the background would have been a nice place and obvious place where to include a way to import dials/bookmarks. But it wasn't there.
I would have given more stars, but this is the most important thing for me, as I don't want to spend a long time just recreating my already existing dials. I will admit it, I am rather upset at the moment, for the lack of support for this very simple and basic feature. I couldn't even find a quick tutorial on how to do it!