I am a bit confused as to why there is no Individual User Accounts authentication option in the latest ASP.NET Core Web API template.
Is it still possible to implement i
I think you can use IdentityServer4 which allows implementing single sign-on and access control for ASP .NET Core Web APIs using protocols like OpenID Connect and OAuth2. It offers integration with ASP.NET Core Identity and Entity Framework Core.
You will need to install to the following nuget package:
Install-Package IdentityServer4
and add the IdentityServer middleware to the HTTP pipeline:
app.UseIdentityServer();
You can find several quick start samples here or follow this article.
Individual User Accounts authentication option for the ASP.NET Core Web API is available in .NET Core 2.0 Preview 1.
Unfortunately .NET Core 2.0 Preview 1 isn't available in VS 2017 release.
But you can install Visual Studio 2017 Preview (you can use it side-by-side with VS 2017 stable version) :