The installation for debian / ubuntu from the cli references a unsecured connection for the repository:
Here the guide:
https://www.spotify.com/de/download/linux/
Here the code where the repository is mentioned (http://repository.spotify.com).
curl -sS https://download.spotify.com/debian/pubkey_6224F9941A8AA6D1.gpg | sudo gpg --dearmor --yes -o /etc/apt/trusted.gpg.d/spotify.gpg
echo "deb http://repository.spotify.com stable non-free" | sudo tee /etc/apt/sources.list.d/spotify.list
It would be very appreciated, if you could enable https for the repository to ensure we actually get the software, you intended for us.
Many thanks!