What do you mean not functioning at all ? 

Can you see Apple TV as one of the options under deezer connect ? 

NO.

I asked the support team if there is a way to control the app installed on Apple TV (Deezer), and the response was positive. Below, I am attaching the reply I received from the Deezer team.

“Hello nir,

Yes, you can control the Deezer app on your Apple TV using your iPhone with the Deezer app on iOS. This is possible through Deezer Connect. Here's how you can do it:

1. On your iPhone, open the Deezer app and go to the player.
2. Select the audio options icon located in the bottom-left corner.
3. Select Deezer Connect.
4. Choose your Apple TV from the list of available devices.

Your music will then play from the selected device. Just make sure both devices are connected to the same Deezer account, connected to the internet, and the Deezer app is open on both devices.”

I don't think I've ever encountered such an unprofessional team. I have a correspondence with the team after I was unsuccessful, and the responses I received were explanations on how to do things, what to check, etc. In the end, someone else from the support team explained to me that it was impossible. What can I say? This is the lowest level of service I've ever experienced.

Hi ​@nirefrati  

Deezer Connect allows you to control your music in another devices but it has to be through the Deezer app, I am afraid 

As mentioned above, you can find more info here