Added official repo once more and it looks like the problem is solved:
# 1. Add the Spotify repository signing keys to be able to verify downloaded packages
sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 931FF8E79F0876134EDDBDCCA87FF9DF48BF1C90
# 2. Add the Spotify repository
echo deb http://repository.spotify.com stable non-free | sudo tee /etc/apt/sources.list.d/spotify.list
# 3. Update list of available packages
sudo apt-get update
"sudo apt update"
then you need to add the Spotify key to the keyring with,
"sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys EFDC8610341D9410"
if you get an error message then you should probably install dirmngr. This fix worked for me and I hope it works for you.