A plug-in that I want to install (Eclipse Jubula Database Drivers) is only available in Eclipse Marketplace. However, I need to install it to an Eclipse package running in a machine that is not connected to the Internet. Is any way to get the update site address so I can download the files for offline installation? This answer solves the problem to download an update site, but I don't see a way to get the update site address from eclipse marketplace
On every plugin page of Eclipse Marketplace, use the rightmost icon underneath the "Install" button. That opens an overlay containing the URL of the update site.