How to authorize a user on a subdomain?

Question

Laravel

There is a site.ru service.
Users register their account in it.
He is given a subdomain.

How to authorize a user at the third level from a second-level domain?
at the second level there should be only a registration/authorization form and any statics.

A user can have multiple accounts. Must be authorized in each office with a separate account.

team1.site.ru - user #1
team2.site.ru - user #3

can't figure out how to do it using Laravel

about the session.domain config. I didn't understand how he could help me.
if you set session.domain => '.site.ru' then this is one authorization for all subdomains. and I need the possibility of different authorizations.

I'm already thinking about a redirect with a signature)