Rated 5 out of 5 stars

For now at least you cannot use the famous app to export to xml or csv. You need to find an older firefox version -v56 for example- install it, disable auto updating, install the Password Exporter, and use the exporting app.
After that you can uninstall the old version use the quantum version. (off course it means you will use another password logger to save logins from then on).