First, Download open vpn certificate from your firewall(SOPHOS)

Copy ssl vpn configuration to “/etc/openvpn”

sudo cp sslvpn-mark.ku-client-config.ovpn /etc/openvpn/vpn.ovpn

Create vpn account and password file for open vpn connection

sudo vim /etc/openvpn/credentials.txt

credentials.txt

vpn account
vpn password

Grant permissions

sudo chmod 600 /etc/openvpn/credentials.txt sudo chown root:root /etc/openvpn/credentials.txt

Install open vpn

sudo apt update
sudo apt upgrade

sudo apt install openvpn

Test the VPN is working

sudo openvpn --config /etc/openvpn/vpn.ovpn --auth-user-pass /etc/openvpn/credentials.txt

sudo vim /etc/systemd/system/openvpn.service

[Unit]
Description=OpenVPN client service
After=network.target

[Service]
Type=simple
ExecStart=/usr/sbin/openvpn --config /etc/openvpn/vpn.ovpn --auth-user-pass /etc/openvpn/credentials.txt
ExecStop=/usr/sbin/openvpn --config /etc/openvpn/vpn.ovpn --auth-user-pass /etc/openvpn/credentials.txt --disconnect
Restart=on-failure

[Install]
WantedBy=multi-user.target 

sudo systemctl enable openvpn.service
sudo systemctl start openvpn.service
sudo systemctl status openvpn.service

sudo reboot

Final

You can try to connect your vpn network's application