1:add repo bigbluebutton2 and install BBB = OK
3:add repo mongo db
root@webinar:/etc/apt/sources.list.d# apt-get update
...
Ign:7 http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4/multiverse arm64 Packages
Ign:8 http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4/multiverse all Packages
Ign:9 http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4/multiverse Translation-en_US
Ign:10 http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4/multiverse Translation-en
Get:12 http://us.archive.ubuntu.com/ubuntu xenial-backports InRelease [102 kB]
Fetched 306 kB in 1min 11s (4,286 B/s)
Reading package lists... Done
W: The repository 'http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4 Release' does not have a Release file.
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.
E: Failed to fetch http://repo.mongodb.org/apt/ubuntu/dists/xenial/mongodb-org/3.4/multiverse/binary-amd64/Packages 403 Forbidden
E: Some index files failed to download. They have been ignored, or old ones used instead.