There are different ways of looking up the zoom user for an indico user:
- matching email addresses on the indico account (we try all emails)
- matching email addresses on the indico account (only for specified domains)
- querying the configured authenticators (e.g. ldap) for the identifier(s) (usually a username) of the user, and prepending
@somedomainto them
At CERN we use the last option because via SSO we enforce username@cern.ch as the email for each Zoom account.
The local Indico username is never used - so in your case it sounds like you want option 2 with the email domain set to ijclab.in2p3.fr. Then you just need to inform your users that in order to use Zoom in Indico they MUST have the givenname.surname@ijclab.in2p3.fr on their account (it doesn’t need to be the primary email, it just need to be there).