Quad9 has several different service offerings for recursive DNS features. Each is represented by a different IP address (or, in some cases, hostname), which you use to configure your systems.
Recursive DNS Server Addresses and Features – Service based configuration:
Recommended: Malware Blocking, DNSSEC Validation (this is the most typical configuration)
IPv4
9.9.9.9
149.112.112.112
IPv6
2620:fe::fe
2620:fe::9
HTTPS
https://dns.quad9.net/dns-query
TLS
tls://dns.quad9.net
In your favorite OS (Ex.: Windows 11 Pro) Make sure that you use DNS over HTTPS to use the dns encryption.
You are now using dns encryption for a better privacy!
Source: https://quad9.net/service/service-addresses-and-features