Hello @zoero77. Thanks for posting in the Spotify Community!
I too long to add TSwift to my Spotify playlists, but alas, not all music is available on Spotify due to agreements with music labels or even the artists themselves. I think the best way to get Swift on Spotify is to petition herself or her music label to make this happen!
In the meantime, enjoy the thousands of other artists on Spotify, and check out this Taylor Swift medley by the Gardiner Sisters!