This code from( Alpaca Streaming API · alpacahq/alpaca-trade-api-csharp Wiki · GitHub ), but i dont get information from market. Why?
I assume that you’ve provided the correct API key/secret for the Live environment and you have an Unlimited data subscription. If you use free-tier IEX data you have to use the Paper environment for streaming data in .NET SDK - it’s not obvious but it’s explicitly described in the GitHub readme document.
And I strongly recommend you check the results of the ConnectAndAuthenticateAsync method call. If you are not authorized you’ll never receive any data. The streaming clients in SDK report all issues using the OnError events because most of the operations are asynchronous.