It sounds like you're talking about browser policies. You should not be editing the registry directly under any circumstances. Edge, like pretty much everything else, has group policies that it uses to enforce settings. You should be configuring these things using GP. You can then apply the policies at the domain, computer or user level depending upon your needs.
It isn't clear to me which policy you're actually trying to set up as basic auth is already turned on in Edge, at least for HTTPS connections. But here is a starter link to the Edge policies. My recommendation is to open the Group Policy Editor on your machine and find the one that seems most appropriate. Policies can be confusing in my experience.