<PackageReference Include="BouncyCastle.Cryptography" Version="2.6.1" />

UrlBase64Encoder

namespace Org.BouncyCastle.Utilities.Encoders { public class UrlBase64Encoder : Base64Encoder { public UrlBase64Encoder() { encodingTable[encodingTable.Length - 2] = 45; encodingTable[encodingTable.Length - 1] = 95; padding = 46; InitialiseDecodingTable(); } } }