Add song to Spotify playlist with curl commands

Configuration
1

Hi there! Right now I’m using IFTTT to add a song I like playing on the radio station on my Sonos to one of my Spotify Playlists, but since they started the paywall I try to stop using it. Another way would be to use curl commands, for example

curl -i -X POST "https://api.spotify.com/v1/playlists/XXX/tracks?uris=spotify%3Atrack%XXX,spotify%3Atrack%XXX" -H "Authorization: Bearer {your access token}" -H "Accept: application/json"

But for this I need the OAuth Token. In some forum posts, I found out its located here (from the Spotify integration)

/home/homeassistant/.homeassistant/.spotify-token-cache

But I can´t find this path in Hassio. I tried

 - platform: command_line
   name: "Spotify Token"
   command: "cat  /home/homeassistant/.homeassistant/.spotify-token-cache | cut -d \" -f 4 | cut -d \" -f 5"

or 

 - platform: command_line
   name: "Spotify Token"
   command: "cat  /config/.spotify-token-cache | cut -d \" -f 4 | cut -d \" -f 5"

but without success. Is there maybe another way to get this OAuth Token?

2

@drimpart Did you eventually managed to get this working?

3

FYI - After finding this, I tried using the Spotify token from the location in the OP to add a track to a playlist using AppDaemon. Turns out that the Spotify grant doesn’t include the scope (playlist-modify-private, playlist-modify-public) to add tracks your playlists.

So this route is not going to work.