It seems it's still not yet fully implemented, but you can take a look on one of m
y older posts on this forum which gives an alternative. Maybe it could help you.
It was about Mixplorer file manager integration with MacroDroid. Mixplorer supports your local storage, ftp, ftps, smb, webdav and lot of other online storages. You can automatically move and copy files and folders from and into these storages with MiXplorer and MacroDroid.