An other way to do this is via command line (in case you are transferring huge amounts of books more often) like:
calibredb export --all --dont-save-cover --dont-update-metadata --dont-write-opf --format epub --replace-whitespace --single-dir --template {author}-{title} --to-dir "\\ANTEC\document_server\ePub Books"
https://manual.calibre-ebook.com/gen...db.html#export