While I dont have a complete answer, sorry. I would try *.spoitfy.com and spotify.com. Then check the filters to see what else its trying to point to. I tried google searching and found some articles but they are on spotifies support pages that I dont have access to.
Here is the page I was able to access: https://community.spotify.com/t5/Desktop-Windows/Spotify-behind-a-https-proxy/td-p/639492
The links are the ones I didnt have access to.
You can always throw a URL profile on a test security entry that simply alerts on all URLs so that you have the URL logs to filter to as the firewall sees them. That's generally what I recommend since you'll see exactly what your firewall is recording and seeing in your deployment whether you have decryption on for the traffic or not, as that will change what your firewall sees/records.
With a quick look you have at least the following in addition to just Spotify.com:
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