I have an MVC site with both MVC controllers and WebApi controllers using cookie authentication. However, I'd like some of the WebApi controllers to authenticate using an Identity 3 server. I checked this answer but the property AuthenticationScheme is not available probably because I'm using Identity 3 (or maybe it's part of .NET core, which I'm not currently using).
How could I tell some WebApi controllers to authenticate against an Identity 3 server?