This is not possible . It was a while back when deezer app was available for Wear OS but it’s not anymore , You can only control the music playing on your phone from the watch .

Hello @Peter Chodelka does your watch has WearOS3?
If that is the case, then the answer is yes, otherwise will be as Noam mentioned.

Check this thread in the community: 
 

With the Google Pixel Watch (WearOS 3.5), music can be played straight from the watch using the deezer app, but it must be paired with an external speaker (in my case, my Pixel Buds).  

Hi @Jaime., there is WearOS 3.5 in the watch and a built-in speaker, but music from Deezer can only be played to bluetooth headphones or an external speaker.

I think, it's the same issue as @Rick.van.Dijk mentioned here:

I understand @Peter Chodelka but I am afraid that it works as @GropplerZorn mentioned above.
I have contacted our devs to doublecheck and as soon as I hear back from them I’ll come back to you to confirm