1.13.2 AnvilGUI from WesJD Version Wrapper

So I'm having a problem with the AnvilGUI from WesJD.
https://github.com/WesJD/AnvilGUI
I use the following Maven code to import the API:

Code (Text):

<dependency>
            <groupId>xyz.upperlevel.spigot.anvilgui</groupId>
            <artifactId>spigot-anvil-gui</artifactId>
            <version>1.3</version>
</dependency>

I can import the AnvilGUI library but I can't see the AnvilGUI.Build Class I can only see AnvilGUI.ClickHandler and AnvilGUI.Slot.
I think that I need a version wrapper like it is said on the GitHub page

but I don't know how to do it.
So my question is how do I add this version wrapper to my project?

 

Ok thanks I will look there for help.