Hello,

> We could try using Galène:

Please do. I am the main developer of Galene.

> Galene proved to be excellent, but the requirement for password to speak
> and use the camera was a bit confusing.

There are two ways to avoid a password in Galene. You can simply set
a user's password to the wildcard password:

    "users": {
        "bob": {"password":{"type":"wildcard"}, "permissions":"present"}
    }

If you want this to apply to arbitrary usernames, set up a wildard user
with a wildcard password:

    "wildcard-user": {"password":{"type":"wildcard"}, "permissions":"present"}

Another solution is to give out a token. Log in as an operator, then
click on your own username in the list on the left, and choose "invite
user".

This is all documented in Galene's README:

https://galene.org/README.html

Please let me know if there's anything else I can help with.

-- Juliusz Chroboczek