Unfortunately, I have no experience with this type of playlist. Streaming via Spotify or Bluetooth is no problem.

It's a bit unclear what exactly you mean by "an external playlist". The device can play "internet radios". To do so, it contacts - according to the manual - a portal of "Frontier Smart Technologies" to download lists of network radio stations, which you can then filter by categories (genre and - as far as I recall - countries and maybe more criteria). It worked but I used that only a few times. I think one can also enter a URL manually, but not sure about that. But playing "an external playlists" - I don't know.