Thanks to debian-Administration.org, this is what I was looking for:
Add /usr/lib/sftp-server to /etc/shells and set this to the users shell. After that, this user has only SFTP access and no SSH access.
Thanks to debian-Administration.org, this is what I was looking for:
Add /usr/lib/sftp-server to /etc/shells and set this to the users shell. After that, this user has only SFTP access and no SSH access.