Yi Camera ffmpeg Issue

Trying to get my Yi camera showing with hassbian.
Has contstant errors in home assistant logs:
FFmpeg fails [Errno 2] No such file or directory: ‘ffmpeg’

Now trying to install FFmpeg has become a nightmare.
What i get at each step:
Tried following steps here https://www.home-assistant.io/components/ffmpeg/#raspbian-debian-jessie-lite-installations
a. Got permission denied on the sources.list file
b. Added source to sources.list manually
c. Ran sudo apt-get update and get error:
W: GPG error: http://ftp.debian.org/debian jessie-backports InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 8B48AD6246925553 NO_PUBKEY 7638D0442B90D010
W: The repository 'http://ftp.debian.org/debian jessie-backports InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
d. Go to get the public keys with: sudo gpg --keyserver subkeys.pgp.net --recv-keys 8B48AD6246925553
e. Get error: gpg: keyserver receive failed: No dirmngr
f. Need to install dirmngr so run: sudo apt-get install dirmngr
g. Get final error
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package dirmngr is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or is only available from another source

E: Package 'dirmngr' has no installation candidate

Now I’m stuck. Any help would be great. I don’t think it’s supposed to be this complicated to add the yi platform…

Try to run those command again:

$ sudo echo “deb http://ftp.debian.org/debian jessie-backports main” >> /etc/apt/sources.list
$ sudo apt-get update
$ sudo apt-get -t jessie-backports install ffmpeg

That just brings me to step a in my original post

I got it. I was using the wrong url for sources. i had to change to
http://ftp.us.debian.org/debian stretch-backports main