Not at all the point of this question, but I showed this title to some friends and had them guess what the acronyms meant because. Its always fun to say phrases that 99% of the population can’t even begin to understand.

I’m certainly no expert in this area, but I believe this is configured in the browser itself? https://support.mozilla.org/en-US/kb/firefox-dns-over-https

Perhaps there’s another way to do it system-wide, but I wouldn’t know it.

Look into systemd-resolved config.

https://www.freedesktop.org/software/systemd/man/resolved.conf.html