We can provide SFTP access for external users (partners) to download/upload files. Best is to create a normal user via the provided scripts User administration, and modify the bash of this user to mysecureshell. The goal of MySecureShell is to offer the power and security of OpenSSH, with enhanced features (like ACL) to restrict connected users. For more documentation see https://mysecureshell.readthedocs.io/en/latest/. To modify the assigned shell of a created user (bash) , you can use smbldap-usermod. Example:

root@sto3:~# smbldap-usermod -s /usr/bin/mysecureshell xre
root@sto3:~# ldapsearch -x uid=xre loginShell
# extended LDIF
#
# LDAPv3
# base <dc=visielab,dc=be> (default) with scope subtree
# filter: uid=xre
# requesting: loginShell 
#

# xre, People, visielab.be
dn: uid=xre,ou=People,dc=visielab,dc=be
loginShell: /usr/bin/mysecureshell

# search result
search: 2
result: 0 Success

# numResponses: 2
# numEntries: 1