>>109051766
Just make a drop-in with the DNS you want, for example:
#!/bin/sh
drop_in="/run/systemd/resolved.conf.d"
mkdir -p "$drop_in"
CNAME="#one.one.one.one"
sudo tee "$drop_in"/dns_servers.conf <<EOF
[Resolve]
DNS=2606:4700:4700::1111${CNAME} 1.1.1.1${CNAME} 2606:4700:4700::1001${CNAME} 1.0.0.1${CNAME}
Domains=~.
DNSOverTLS=yes
EOF
systemctl restart systemd-resolved
Make the drop-in in /etc/systemd to be permanent