How do I get a list of current subscribers to a channel?

How do I get a list of subscribers? Reading the documentation I understand I need to send a header “Client-ID” along with my request, I do it like it this in C#
Httpclient.DefaultRequestHeaders.Add(“Client-ID”, “[myclientID]”);

But I still get access denied back from the API. It works fine with followers and things you dont need to be authenticated for

The GET /channels/:channel/subscriptions endpoint requires authentication as the channel owner. You will need to generate an OAuth token with the channel_subscriptions scope and send that along with your request. See the authentication documentation for more info about generating and using tokens.

If you need to Authenticate as the channel owner then how does applications like SubAlert see when a new account subscribes to a channel?

The broadcaster will need to “login” to the application to provide their token.

Oh I see. Thank you very much for your help!