Edit file /etc/dhcp/dhclient.conf
supersede domain-name "ims.mnc001.mcc001.3gppnetwork.org";
prepend domain-name-servers 192.168.0.189, 192.168.0.1;
edit file /etc/systemd/resolved.conf
DNS=192.168.0.189
FallbackDNS=192.168.0.1
Domains=ims.mnc001.mcc001.3gppnetwork.org
restart resolved
systemctl restart systemd-resolved
check resolved status
resolvectl status
Global
Protocols: +LLMNR +mDNS -DNSOverTLS DNSSEC=no/unsupported
resolv.conf mode: foreign
DNS Servers: 192.168.0.189
Fallback DNS Servers: 192.168.0.1
DNS Domain: ims.mnc001.mcc001.3gppnetwork.org
Link 2 (enp0s3)
Current Scopes: LLMNR/IPv4 LLMNR/IPv6
Protocols: -DefaultRoute +LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
try restarting the server to confirm if the entries in resolved.conf are persistent or not.
after restart check
$ cat /etc/resolv.conf
domain ims.mnc001.mcc001.3gppnetwork.org
search ims.mnc001.mcc001.3gppnetwork.org
nameserver 192.168.0.189
nameserver 192.168.0.1
nameserver 192.168.0.1
Enjoy ;)