FROM:

elif [[ "$os" == *"Debian"* ]] || [[ "$os" == *"Ubuntu"* ]]; then
        echo "Calling OpenVPN as service..."
        startas="service"
        ${SERVICE_INTERFACE} ${OPENVPN_SERVICE} start ${HMA_VPN_NAME} > /dev/null

TO:

elif [[ "$os" == *"Debian"* ]] || [[ "$os" == *"Ubuntu"* ]]; then
        echo "Calling OpenVPN as service..."
        startas="service"
        $openvpn --daemon --config /etc/openvpn/${HMA_VPN_NAME}.conf