<PackageReference Include="System.Configuration.ConfigurationManager" Version="6.0.0-preview.1.21102.12" />

ConfigurationSettings

public sealed class ConfigurationSettings
Provides runtime versions 1.0 and 1.1 support for reading configuration sections and common configuration settings.
using System.Collections.Specialized; namespace System.Configuration { public sealed class ConfigurationSettings { [Obsolete("This property is obsolete, it has been replaced by System.Configuration.ConfigurationManager.AppSettings")] public static NameValueCollection AppSettings { get { return ConfigurationManager.AppSettings; } } internal ConfigurationSettings() { } [Obsolete("This method is obsolete, it has been replaced by System.Configuration.ConfigurationManager.GetSection")] public static object GetConfig(string sectionName) { return ConfigurationManager.GetSection(sectionName); } } }