How to stream a M3U file on iOS devices in background?

[Years ago I asked how to stream m3u radio files (music) on the iPhone](https://apple.stackexchange.com/questions/322850/how-to-stream-a-m3u-file-on-ios-devices) . Revisiting my question from the past, none of the IPTV players allow to play the music when the app is in the background / when the iPhone is in standby. I think this is the case, because none those players use the default music player interface, as they are designed to play video, not audio. My question is: Is there any app that plays local m3u file radio streams through the default media player interface, so that I can enjoy radio while the iPhone is in standby? The best thing would be an alternative to RadioDroid for iOS, but it needs to come with a m3u importer. The file is locally accessible only, because it gets synced via Syncthing. To clarify, with "local m3u file radio" I mean a m3u file stored in the local iPhone storage that contains of EXTINF entries that point to online radio stations (http-URLs), such as:

#EXTM3U
#RADIOBROWSERUUID:9617a958-0601-11e8-ae97-52543be04c81
#EXTINF:-1,Radio Paradise (320k)
http://stream-uk1.radioparadise.com/aac-320 

#RADIOBROWSERUUID:96156a3e-0601-11e8-ae97-52543be04c81
#EXTINF:-1,Deep House Lounge
http://198.15.94.34:8006/stream 

I want to emphasize that I cannot import the m3u file itself via URL, as it's not available online.