Use audio stream overs ssh with ffmpeg on web page

I need to broadcast the audio stream (WiFi camera at my home) on the website hosted on a VPS.

Here is the command executed from my home:

ffmpeg -i "rtsp://172.16.0.201:554/user=admin&password=root&channel=1&stream=1.sdp" -bufsize 24k -vn -acodec copy -f mpegts - | ssh -p 22222 root@mydomain.org 'ffmpeg -i - -vn -acodec libvorbis -ac 1 -ar 8000 -ab 64k -f mpegts "rtsp://127.0.0.1:53350/live.sdp"'

It seems to work because I get

ffmpeg version n4.2.2 Copyright (c) 2000-2019 the FFmpeg developers
  built with gcc 9.2.0 (GCC)
  configuration: --prefix=/usr --disable-debug --disable-static --disable-stripping --enable-fontconfig --enable-gmp --enable-gnutls --enable-gpl --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libdav1d --enable-libdrm --enable-libfreetype --enable-libfribidi --enable-libgsm --enable-libiec61883 --enable-libjack --enable-libmfx --enable-libmodplug --enable-libmp3lame --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libv4l2 --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxcb --enable-libxml2 --enable-libxvid --enable-nvdec --enable-nvenc --enable-omx --enable-shared --enable-version3
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
ffmpeg version 4.1.4-1~deb10u1 Copyright (c) 2000-2019 the FFmpeg developers
  built with gcc 8 (Debian 8.3.0-6)
  configuration: --prefix=/usr --extra-version='1~deb10u1' --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
  libavutil      56. 22.100 / 56. 22.100
  libavcodec     58. 35.100 / 58. 35.100
  libavformat    58. 20.100 / 58. 20.100
  libavdevice    58.  5.100 / 58.  5.100
  libavfilter     7. 40.101 /  7. 40.101
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  3.100 /  5.  3.100
  libswresample   3.  3.100 /  3.  3.100
  libpostproc    55.  3.100 / 55.  3.100
Guessed Channel Layout for Input Stream #0.1 : mono
Input #0, rtsp, from 'rtsp://172.16.0.201:554/user=admin&password=root&channel=1&stream=1.sdp':
  Metadata:
    title           : RTSP Session
  Duration: N/A, start: 0.000000, bitrate: N/A
    Stream #0:0: Video: h264 (Main), yuv420p(progressive), 640x360, 12 fps, 12 tbr, 90k tbn, 24 tbc
    Stream #0:1: Audio: pcm_alaw, 8000 Hz, mono, s16, 64 kb/s
[mpegts @ 0x5582b6b14c40] frame size not set
Output #0, mpegts, to 'pipe:':
  Metadata:
    title           : RTSP Session
    encoder         : Lavf58.29.100
    Stream #0:0: Audio: pcm_alaw, 8000 Hz, mono, s16, 64 kb/s
Stream mapping:
  Stream #0:1 -> #0:0 (copy)
Press [q] to stop, [?] for help
size=     146kB time=00:00:17.06 bitrate=  70.0kbits/s speed=1.16x

But when I look on the VPS I don't see the port open with netstat.

Yet the process seems to be running

root     21801  0.2  2.1 265916 42188 ?        SLs  15:03   0:00 ffmpeg -i - -vn -acodec libvorbis -ac 1 -ar 8000 -ab 64k -f mpegts rtsp://127.0.0.1:53350/live.sdp

I thought I would access the feed with a simple html page with this kind of code

<audio controls>
<source src=rtsp://127.0.0.1:53350/live.sdp" type="audio/ogg" />
<em>Désolé, votre navigateur ne supporte pas l'audio HTML5</em>
</audio>

iptables

Chain INPUT (policy DROP)
....
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:53350
ACCEPT     udp  --  anywhere             anywhere             udp dpt:53350
....
Chain FORWARD (policy DROP)
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:53350
ACCEPT     udp  --  anywhere             anywhere             udp dpt:53350
....
Chain OUTPUT (policy DROP)
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:53350
ACCEPT     udp  --  anywhere             anywhere             udp dpt:53350
....