I can tell you what worked for me, what i did was this connected any Bluetooth headphones to your Apple Watch, unfortunately, Spotify on Apple Watch currently doesn’t support direct music playback. This means you can’t download songs or stream music directly from the Spotify app on your watch. Here’s what you can do:-
1. Use Spotify as a remote control:-
- Pair your Bluetooth headphones with your Apple Watch using the Settings app on your watch.
- Open the Spotify app on your iPhone.
- You can then use the Spotify app on your Apple Watch as a remote to control playback on your iPhone, including play/pause, skip tracks, and adjust volume.
2. Use Apple Music or downloaded music:-
- If you’re subscribed to Apple Music, you can download playlists or albums for offline listening on your Apple Watch. This allows you to play music directly on your Watch with connected headphones without needing your iPhone.
- Alternatively, you can transfer music files (purchased or through iTunes Match) to your Apple Watch for offline listening.
More details instruction below.
https://www.youtube.com/watch?v=qDUrOAlH0IU&ab_channel=TheGeekPage