How to check online state of the special user in the special channel

I am working on integrating Twitch API into the website.
I need if the user is online in the special channel.
And I need if the user puts the message in the special channel.
I am searching on Twitch API reference for 2 days but I can’t find how to get it.
Could you please help me?

What do you mean “special channel”

Stream Status is returned via

Get Streams -
EventSub -

Thanks for your swift response.
I mean:
For example: Imagine that the user “A” is viewing a vid or putting a message in the channel “test_chan”
I have to get the state of the user “A”.
In other words, I have to get the online/offline state of user “A” in the channel “test_chan”. And the count of his messages as well…

You can’t

A users online state and current viewing data is not provided by the API
And additionally is governed by various privacy laws.

Hi, Barry
Thanks for your help!