New app feature replacement requests

Hello

I've been desperately holding on to the old app after the car crash that is the new app which ended up on our ipad.

One of the features missing in the new app which I suppose is quite niche but means a lot to us is the "add to Spotify playlist" option on the track now playing. When listening to new (to us) music we like to add tracks to our own lists as we go, but to Spotify playlists not sonos ones because we want to be able to use those lists on the train etc. 

It's missing from the new app, how do we request it?

Ta