Install systemd-resolved
# apt-get install systemd-resolved
Enable it
# systemctl enable systemd-resolved
Old fashion /etc/resolv.conf
# Generated by NetworkManager
nameserver 45.90.28.186
nameserver 8.8.8.8
nameserver 1.1.1.1
Change/Edit configuration file /etc/systemd/resolved.conf
DNS=45.90.28.186 8.8.8.8 1.1.1.1
DNSOverTLS=yes
Restart systemd-resolved
# systemctl restart systemd-resolved
Test it
# nslookup duckduckgo.com
Server: 127.0.0.53
Address: 127.0.0.53#53
Non-authoritative answer:
Name: duckduckgo.com
Address: 20.43.161.105
Done.
