I applaud your desire to make use of the Twitch API, but there are several issues with your code.
You invoke neither MainNot nor CallsAsync. Since you copied this verbatim from the TwitchLib repository, I understand why you renamed Main to MainNot. However, that example code as given in the repository, is incomplete and incorrect.
Your click handlers are empty. You don’t need Label1_Click since you don’t need such a handler for your label. (It’s rare to ever need such a handler.) Button1_Click is where you want to invoke CallsAsync. In Button1_Click, add this line: var task = CallsAsync();.
The invocation of GetChannelFollowersAsync is incorrect. It does not accept channel names, only channel IDs. That method fails silently if given a channel name. Replace elixist with 66227321.
Move the contents of the MainNot method into the Form1 constructor. Since you care only about getting the follower count for a channel, delete all code from CallsAsync except the invocation of GetChannelFollowersAsync. After that line, add this line: Label1.Text = channelFollowers.Total.ToString();. Now, you are ready to run the application and click the button.
Also, you have leaked an access token for your application. I suggest you invalidate it immediately to prevent someone from using it for nefarious means. In future posts, do not include an access token.