User/Channel Not Found?

I have my 1st extension setup and the Twitch Auth returns the following data:
channelId: 240173824

However, when I try to call GetChannelById with the client-id passed in, I get a 404 error ‘channel not found’.

The get URL I’m calling is
and the headers have the client-id=‘my client id’.

The same error goes if I try to use the same ID and call the GetUserById endpoint.

Any ideas what I’m doing wrong here?