• create the user

sudo adduser access

• assign a password to the new user

sudo passwd access

• create the directory for file upload

sudo mkdir -p /var/sftp/uploads

• establish the root user as owner

sudo chown root:root /var/sftp

• grant write permissions to the root user and read to the other users

sudo chmod 755 /var/sftp

• modify the owner of uploads to be the user access

sudo chown access:access /var/sftp/uploads

• restrict the access by the terminal to the user access

sudo vi /etc/ssh/sshd_config

• In the final part of the file, add followings

Match User access

ForceCommand internal-sftp
PasswordAuthentication yes
ChrootDirectory /var/sftp
PermitTunnel no
AllowAgentForwarding no
AllowTcpForwarding no
X11Forwarding no

• Save the changes using the key combination

ESC + :wq

• apply the changes in SSH

sudo systemctl restart sshd

• SSH connection

ssh acces@{server_ip}

• Use the sftp protocol

sftp access@{server_ip}