When we create an Azure SQL server, we can opt to have it authenticate users against Azure AD, but I don't see any option during creation (or afterward in the settings pages of the server instance) to select which directory, if the account has more than one; it seems to just use the one marked as "default" in the directories list. The account I'm creating the SQL server in has 4 directories, two normal and two B2C:

The "setup a new SQL server" wizard offers "Azure AD" as an option, but not any choice of which:

How do we change the directory a particular SQL server uses? And can it be an Azure AD B2C directory, or does it have to be an Azure AD type directory?