@iarganda In case you need to do that, I added you as an uploader for the Java-8 site. There will come a day when all uploads are done by Jenkins, and the way to get your new stuff to an update site is to push to a Git repository. But that day has not yet arrived.
You just set your credentials in the Manage Update Sites dialog box, the same way you would for the Fiji update site.
Use webdav:Iarganda for the Host, and ./ for the Directory on Host.