Hey^^ so I use Youtube Musig and it works on the watch. Simply connect the watch with the smartphone and then you can control the volume, start and pause, select the next and previous song with the watch. The name and artist of the song are displayed. Unfortunately, song search on the watch is not possible. You also need headphones, as the watch has no speakers. If it works with Youtube music, Spotify should also work in my opinion ;)

Hey :)

Not really, because it's more of a fitness tracker per se. Notifications etc. are displayed, but as far as I can tell, you can't install any additional apps.

Maybe you should specify what you mean by "use Spotify" :-)
Listening to music without a mobile phone?