You should only ever allow SMB access over a LAN. The only time you should ever access SMB remotely is through a VPN (i.e. as a member of the LAN). SMB was never intended to be used out in the open...

I'm not sure what protocols Aptava supports but personally a secure one that is safe online such as SFTP would be the way to go. Even if it doesn't support it OOTB I'm sure that there would be a plugin for it.

FWIW TKL already has SFTP configured and enabled; although the setup of a new user who is part of the www-data group would probably be best.