Enable basic auth for wallbag export by adding these configuration statements (files are in app/config/)

routing.yml

backup:
    path: "/backup/{category}.{format}"
    defaults:
        _controller: WallabagCoreBundle:Export:downloadEntries
    requirements:
        category: all|unread|starred|archive
        format: epub|mobi|pdf|json|xml|txt|csv

security.yml

firewalls:
    backup:
        pattern: ^/backup/.*
        stateless: true
        http_basic:
            realm: "Wallabag"
            provider: fos_userbundle