Tvheadend

Hi, need some help. just fresh installed debian 9 and followed the wiki, but when i make a apt update i get this error:

root@debian:~# wget -qO- https://doozer.io/keys/tvheadend/tvheadend/pgp | apt-key add -
OK
root@debian:~# echo "deb http://apt.tvheadend.org/stable stretch main" | tee -a /etc/apt/sources.list.d/tvheadend.list
deb http://apt.tvheadend.org/stable stretch main
root@debian:~# apt update
Ign:1 http://ftp.dk.debian.org/debian stretch InRelease
Hit:2 http://ftp.dk.debian.org/debian stretch-updates InRelease
Hit:4 http://ftp.dk.debian.org/debian stretch Release
Hit:5 http://security.debian.org/debian-security stretch/updates InRelease
Ign:3 https://apt.tvheadend.org/stable stretch InRelease
Err:7 https://apt.tvheadend.org/stable stretch Release
404 Not Found
Reading package lists... Done
E: The repository 'http://apt.tvheadend.org/stable stretch Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.