The main plugin manager repository, as well as most of the released plugins, are hosted on gitlab.com. If you for any reason cant access gitlab.com a mirror is provided at: https://plugins.grogra.de/

To enable this mirror in the plugin manager, go to the “Repositories” tab and add a new repository (press the “Add a repository” button). Set the new repository to “https://plugins.grogra.de/plugins.json” and active it. At this point you might also deactivate the “grogra.gitlab.io” repository, but this step is not necessary.