<PackageReference Include="System.Configuration.ConfigurationManager" Version="9.0.0-preview.6.24327.7" />

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 { [System.Obsolete("ConfigurationSettings.AppSettings has been deprecated. Use System.Configuration.ConfigurationManager.AppSettings instead.")] public static NameValueCollection AppSettings { get { return ConfigurationManager.AppSettings; } } internal ConfigurationSettings() { } [System.Obsolete("ConfigurationSettings.GetConfig has been deprecated. Use System.Configuration.ConfigurationManager.GetSection instead.")] public static object GetConfig(string sectionName) { return ConfigurationManager.GetSection(sectionName); } } }