Hi Hamza0077,
Have you checked to ensure your watchOS and iOS on your paired iPhone is fully updated? If needed, check out the articles below to assist.
Update your iPhone, iPad, or iPod touch
Update your Apple Watch
Once fully updated, check for any updates for the Spotify app. How to manually update apps on your Apple device
If the issue continues, restart both your iPhone and Apple Watch.
Restart your iPhone
Restart your Apple Watch
Once powered back on, ensure you're connected to Wi-Fi, cellular data or both and test. If the issue continues and it's only with the Spotify app, reach out to the app developer to further assist.
How to contact an app developer
You may also find helpful information on their community support forum here: App not working Apple Watch Series 7
Best!