AccountController.cs

public class AccountController : Controller 
{
    private UserManager<AppUser> userManager;
    private SignInManager<AppUser> signInManager;
    
    // RavenDB.Identity provides a UserManager and SignInManager for dependency injection.
    public AccountController(UserManager<AppUser> userManager, SignInManager<AppUser> signInManager)
    {
        this.userManager = userManager;
        this.signInManager = signInManager;
    }
    
    public async Task<IActionResult> LogIn(LoginViewModel model)
    {
        // Use the standard Identity APIs, like .PasswordSignInAsync
        await this.signInManager.PasswordSignInAsync(
            model.Email, 
            model.Password, 
            model.RememberMe, 
            lockoutOnFailure: false);
        ...
    }
}