It's currently an experimental feature not enabled by default and with no UI to ...

		GraemeL on Aug 5, 2018 \| parent \| context \| favorite \| on: Firefox’s Trusted Recursive Resolver DNS feature i... It's currently an experimental feature not enabled by default and with no UI to change settings outwith about:config. In the current release version of Firefox (61.0.1) the provider parameter (network.trr.uri) is blank and not set to Cloudfare out of the box.