Thank you, now it works!
If you don’t mind why you don’t recommend using nordVPN DNS?
For my future reference:
cat<<‘EOF’ >> /etc/openvpn/<YOUR_CLIENT_FILE_NAME>.ovpn
script-security 2
up /etc/openvpn/updns
down /etc/openvpn/downdns
EOF
cat<<‘EOF’ > /etc/openvpn/updns
#!/bin/sh
mv /tmp/resolv.conf.auto /tmp/resolv.conf.auto.hold
echo $foreign_option_1 | sed -e ‘s/dhcp-option DOMAIN/domain/g’ -e ‘s/dhcp-option DNS/nameserver/g’ > /tmp/resolv.conf.auto
echo $foreign_option_2 | sed -e ‘s/dhcp-option DOMAIN/domain/g’ -e ‘s/dhcp-option DNS/nameserver/g’ >> /tmp/resolv.conf.auto
echo $foreign_option_3 | sed -e ‘s/dhcp-option DOMAIN/domain/g’ -e ‘s/dhcp-option DNS/nameserver/g’ >> /tmp/resolv.conf.auto
EOF
cat<<‘EOF’ > /etc/openvpn/downdns
#!/bin/sh
mv /tmp/resolv.conf.auto.hold /tmp/resolv.conf.auto
EOF
chmod 755 /etc/openvpn/updns
chmod 755 /etc/openvpn/downdns