def get_backends_url(config):
    """Return the URL for a backend."""
    hub = config.get('hub', None)
    group = config.get('group', None)
    project = config.get('project', None)

    if hub and group and project:
        return '/Network/{}/Groups/{}/Projects/{}/devices/v/1'.format(hub, group,
                                                                      project)
    return '/Backends/v/1'