Mozilla has decided to roll out the DNS over HTTPS (DoH) feature by default for Canadian Firefox users later this month. The move comes after DoH has already been offered to US-based Firefox users since 2020. Mozilla has announced partnering with Canadian Internet Registration Authority (CIRA) as the choice of its DoH provider for Firefox Canada users. DoH encrypts regular DNS traffic over HTTPS with both DNS requests and responses being transmitted over port 443, making the traffic blend right in with regular traffic to HTTPS websites.
Source: https://www.bleepingcomputer.com/news/security/mozilla-firefox-to-roll-out-dns-over-https-for-canadian-users/