Correct syntax to record mp3 from m3u url with ffmpeg

I would like to record the stream from www.dradio.de/streaming/dlf.m3u with ffmpeg.

When accessing the file with the browser, a file gets downloaded with the following contents:

http://st01.dlf.de/dlf/01/128/mp3/stream.mp3

When I try to record the m3u url with:

ffmpeg -playlist 1 -i http://www.dradio.de/streaming/dlf.m3u output.mp3

I get an error message:
http://www.dradio.de/streaming/dlf.m3u: Invalid data found when processing input

The mp3 url itself can be downloaded with:

ffmpeg -i http://st01.dlf.de/dlf/01/128/mp3/stream.mp3 output.mp3

As I do not want to process the contents of the m3u file (I expect it to be more complex in other cases):

What is the correct syntax when I want to use the m3u url only?