System.Text.Encoding.CodePages by Microsoft

<PackageReference Include="System.Text.Encoding.CodePages" Version="9.0.0" />

.NET API 762,656 bytes

 CodePagesEncodingProvider

public sealed class CodePagesEncodingProvider : EncodingProvider
Provides access to an encoding provider for code pages that otherwise are available only in the desktop .NET Framework.
public static EncodingProvider Instance { get; }

Gets an encoding provider for code pages supported in the desktop .NET Framework but not in the current .NET Framework platform.