services.AddAuthentication(IdentityServerAuthenticationDefaults.AuthenticationScheme)
.AddJwtBearer(
options =>
{
    options.Authority = "https://youridentityserver3instance.com/identity";
    //options.RequireHttpsMetadata = false; // If you don't use HTTPS uncomment.
    options.SaveToken = true;  // Allows the API to reuse it's token later in client calls.
    options.TokenValidationParameters = new Microsoft.IdentityModel.Tokens.TokenValidationParameters();
    options.TokenValidationParameters.ValidateAudience = false; // Comment this out if supplying an audience.
    //options.Audience = "myservicename";

    // If you need to fix claim mapping to be backwards compatible.
    options.SecurityTokenValidators.Clear();
    options.SecurityTokenValidators.Add(new JwtSecurityTokenHandler
    {
        InboundClaimTypeMap = new Dictionary<string, string>
        {
            { "name",System.Security.Claims.ClaimTypes.Name },
            { "role", System.Security.Claims.ClaimTypes.Role }
        }
    });
});

// If you need to fix claim mapping to be backwards compatible.
JwtSecurityTokenHandler.DefaultInboundClaimTypeMap = new Dictionary<string, string>
{
    { "name",System.Security.Claims.ClaimTypes.Name },
    { "role", System.Security.Claims.ClaimTypes.Role }
};

// Add cookie authentication.
services.AddAuthentication(CookieAuthenticationDefaults.AuthenticationScheme)
    .AddCookie(
    options =>
    {
        options.ExpireTimeSpan = new TimeSpan(0, 30, 0);
        options.SlidingExpiration = true;
    });

// Add OpenId authentication.
services.AddAuthentication(OpenIdConnectDefaults.AuthenticationScheme)
    .AddOpenIdConnect(
    options =>
    {
        options.Authority = "https://youridentityserver3instance.com/identity";
        options.ClientId = "myclient";
        options.ClientSecret = "mysecret";
        options.SignInScheme = CookieAuthenticationDefaults.AuthenticationScheme;
        options.ResponseType = "code id_token token";
        options.UseTokenLifetime = false;
        options.SignedOutRedirectUri = "http://localhost:2000/";

        options.SaveTokens = true; // Allows the MVC app to reuse it's token later in client calls.
        options.GetClaimsFromUserInfoEndpoint = true;
        options.Scope.Add("openid");
        options.Scope.Add("profile");
        options.Scope.Add("address");
        options.Scope.Add("offline_access");
        options.Scope.Add("roles");
    });