<PackageReference Include="System.Configuration.ConfigurationManager" Version="4.6.0" />

AppSettingsSection

public sealed class AppSettingsSection : ConfigurationSection
Provides configuration system support for the appSettings configuration section. This class cannot be inherited.
public string File { get; set; }

Gets or sets a configuration file that provides additional settings or overrides the settings specified in the appSettings element.

public KeyValueConfigurationCollection Settings { get; }

Gets a collection of key/value pairs that contains application settings.

public AppSettingsSection()

Initializes a new instance of the AppSettingsSection class.