Withings - tracking multiple persons

Hello
Recently I started to play with Withings Sleep, wanting to achieve disabling lights when my girlfriend goes asleep.
Due to problems with retrieved data reliability (actually not matching reality at all) I want to ask about name values expected to be put in integration config, and their relation to Withings account name. Is it any?
Can I retrieve my girlfriend data just by her name (which name? first, last or full one? Then can I retrieve data of anybody on this planet without any authorization?

Or maybe every person must have it’s own “developer account” created to retrieve his personal data. But than what is ability to configure more names in integration config for?

BTW is the integration tested for retrieving data for multiple persons? When I configured it for two persons, I was receiving a lot of authentication errors, incl rejecting integration (there was a message that I need to remove integration and re-connect again)

I’m using recent hasio on RPi4 and NabuCasa for connectivity from outside (incl. Withings authorization)

Thanks for any guidelines in advance
with regards
MK