You can try checking the releases on github to find an older version. Downloading the .mpk is what you would need.
Also if you just want the java action from this module, you can right click it > export document to file, and that will export the specific java action. Then you can go to your project where you want to import it. Right click the module you want to import it into and click import document from file. Same thing applies to microflows and pages.
I have the widget implemented and almost fully functional, I am looking to add the export to excel java action which is only in their demo project.
I searched the Github and only saw previous versions of the widget (.mpk) file not any older versions of the demo project.
I have tried just exporting the java action alone, but since the project it was a part of was created in 6.10.10 it cannot be imported into a 6.10.9 project.