'ISystemClock' is obsolete: 'Use TimeProvider instead.'

'OAuthHandler<T>.OAuthHandler(IOptionsMonitor<T>, ILoggerFactory, UrlEncoder, ISystemClock)' is obsolete: 'ISystemClock is obsolete, use TimeProvider on AuthenticationSchemeOptions instead.'

Possible null reference argument for parameter 's' in 'byte[] Encoding.GetBytes(string s)'.

Possible null reference argument for parameter 's' in 'byte[] Encoding.GetBytes(string s)'.

'Exception.Exception(SerializationInfo, StreamingContext)' is obsolete: 'This API supports obsolete formatter-based serialization. It should not be called or extended by application code.' (https://aka.ms/dotnet-warnings/SYSLIB0051)

'Exception.Exception(SerializationInfo, StreamingContext)' is obsolete: 'This API supports obsolete formatter-based serialization. It should not be called or extended by application code.' (https://aka.ms/dotnet-warnings/SYSLIB0051)

Possible null reference return.

Use IHeaderDictionary.Append or the indexer to append or set headers. IDictionary.Add will throw an ArgumentException when attempting to add a duplicate key. (https://aka.ms/aspnet/analyzers)

Possible null reference argument for parameter 's' in 'byte[] Encoding.GetBytes(string s)'.