How to output/pipe information from silencedetect filter

**Describe the bug**
Hello! I was trying to save the silences produced by the filter in a .txt file for reference

**To Reproduce**
Steps to reproduce the behavior:
1.` await ffmpeg.run(
'-i',
'test.aac',
'-af',
'silencedetect=d=0.8',
'-f',
'null',
'-',
'2>',
'silences.txt'
);`
2. See error
[fferr] Input #0, aac, from 'test.aac':
log.js:15 [fferr] Duration: 00:00:54.94, bitrate: 127 kb/s
log.js:15 [fferr] Stream #0:0: Audio: aac (LC), 32000 Hz, mono, fltp, 128 kb/s
log.js:15 [fferr] [NULL @ 0x1a6c980] Unable to find a suitable output format for '2>'
log.js:15 [fferr] 2>: Invalid argument
log.js:15 [fferr] Conversion failed!
log.js:15 [ffout] FFMPEG_END

the command works when its just
` await ffmpeg.run(
'-i',
'test.aac',
'-af',
'silencedetect=d=0.8',
'-f',
'null',
'-'
);`

**Expected behavior**
Expected that a .txt file with the logs for silences to be produced in memfs. It worked with vanilla ffmpeg
Not sure how to write this command.

Have seen other discussions where the desired log in parsed from the the logger, is this the only way?
[https://github.com/ffmpegwasm/ffmpeg.wasm/issues/277](url)