Stream tweets of specific account\s doesn't work with Tweetinvi

Question

I'm trying to use tweetinvi to follow specific users in a streaming mode. I try to test AddFollow with my twitter account (tweet something and see if it catches that) - doesn't work (BTW - AddTrack do work)

1. How do I get my twitter user ID (is http://mytwitterid.com/ is the formal User ID from tweetinvi perspective?

2. How else can I test it - or what is wrong here?

    var filteredStream = Stream.CreateFilteredStream();
   
       filteredStream.AddFollow(myTwitterUserId);            
   
       filteredStream.MatchingTweetReceived += (sender, args) =>{
        Console.WriteLine(args.Tweet.Text);};
   
       Thread t = new Thread(() =>
       {
           // Start the stream matching any of the conditions
           filteredStream.StartStreamMatchingAllConditions();
       });
   
   t.Start();