从.NET Core 3.1到.NET 5，WWW-Authenticate头中的Realm已经被删除了，现在使用以下代码将认证方案名称添加到WWW-Authenticate头中：

• 使用命名策略：

services.AddAuthorization(options =>
{
    options.DefaultPolicy = new AuthorizationPolicyBuilder()
        .AddAuthenticationSchemes("Bearer") // 认证方案名称
        .RequireAuthenticatedUser()
        .Build();
});

services.AddAuthentication("Bearer")
    .AddJwtBearer(options =>
    {
        options.Authority = "https://localhost:5001"; // 认证地址
        options.Audience = "api1"; // 目标资源
    });

• 使用实例策略：

services.AddAuthentication(options =>
{
    options.DefaultScheme = JwtBearerDefaults.AuthenticationScheme;
})
.AddJwtBearer(options =>
{
    options.Authority = "https://localhost:5001"; // 认证地址
    options.Audience = "api1"; // 目标资源
});

services.AddAuthorization(options =>
{
    options.DefaultPolicy = new AuthorizationPolicyBuilder(JwtBearerDefaults.AuthenticationScheme)
        .RequireAuthenticatedUser()
        .Build();
});