Tvheadend

Hi,
I'm trying to add an IPTV list in TVH but always fails. I type the following data:

pipe:///usr/bin/ffmpeg -i https://rtvelivestream.akamaized.net/la1_dvr.m3u8 -c copy -f mpegts pipe:1

If I put the url in VLC, it opens normally the tv channel. Where's my fail?

Best regards