Like Google Chrome, the Microsoft Edge will not really use it DoH, unless you are using a DNS server that supports DoH. There are many options: Google Public Cloud, Cloudflare, and even Comcast DNS all support these features.
How to enable DNS via HTTPS in Edge
To activate DoH in Edge type the internal “edge: // flags # dns-over-https” in the address bar and press Enter.
To the right of "Secure DNS Lookups", click on the arrow to open the drop-down menu. Select "On".
You will need to restart your browser to apply these changes. Click the "Restart" button below the page.
How to switch to a DNS compatible server DoH
You can check if DNS over HTTPS works with Edge by going to Browsing Experience Security Check of Cloudflare. Start the test by clicking the check my browser button to see if "Secure DNS" is enabled or not.