title: Guid Instead of string for primary key / ID for ASP.Net Core 3.1 Identity
body: <p>This no longer works with ASP.Net Core 3.1 / .Net Core 3.1 </p>
  
  <p><a href="https://stackoverflow.com/a/37173202/1698480">https://stackoverflow.com/a/37173202/1698480</a></p>
  
  <p>Compile error:'IdentityBuilder' does not contain a definition for 'AddEntityFrameworkStores' and no accessible extension method 'AddEntityFrameworkStores' accepting a first argument of type 'IdentityBuilder' could be found (are you missing a using directive or an assembly reference?)    WebSite.Site    C:\WorkSource....\Startup.cs   32  Active</p>
  
  <pre><code>public class ApplicationUser : IdentityUser&lt;Guid&gt; { }
  public class Role : IdentityRole&lt;Guid&gt; { }
  
  public class ApplicationDbContext : IdentityDbContext&lt;ApplicationUser, Role, Guid&gt;
  {
     ...
  }
  
  public class Startup
  {
      ...
      public void ConfigureServices(IServiceCollection services)
      {
          services.AddIdentity&lt;ApplicationUser, Role&gt;()
              .AddEntityFrameworkStores&lt;ApplicationDbContext, Guid&gt;()
              .AddDefaultTokenProviders()
              .AddUserStore&lt;UserStore&lt;ApplicationUser, Role, ApplicationDbContext, Guid&gt;&gt;()
              .AddRoleStore&lt;RoleStore&lt;Role, ApplicationDbContext, Guid&gt;&gt;();
  
      }
  }
  </code></pre>
  
  <p>If I just remove the Guid generic arg like this:</p>
  
  <pre><code>.AddEntityFrameworkStores&lt;ApplicationDbContext, Guid&gt;()
  </code></pre>
  
  <p>then I get browser error: This localhost page can’t be foundNo webpage was found for the web address: <a href="http://localhost:50827/Account/Login?ReturnUrl=%2F" rel="nofollow noreferrer">http://localhost:50827/Account/Login?ReturnUrl=%2F</a></p>
  
  <p>How can I do this?  thanks</p>