can't do a sign up flow with email verification

[HananArgov]

Hi all,
i've been trying for a few days now to do a simple signin flow using email verification, but i keep getting into the same wall.
the flow is pretty simple:

1. go to site
2. enter email address
3. click on the link in the email
4. the link redirects to site, and will log me in automatically

i've got issues that since the link redirects from a different site, i'm getting "unauthorized login" error, instead of logging in.
i can't use cy.visit on the same spec, since the initial visit and the verification link are on different domains, which is forbidden in cypress.

i've tried to go to the link from a next spec, but since it's a redirection, saving the cookies don't help, since cypress will discard the cookies on account to trying to visit a different domain (i think that what happens)
and if i try to add headers to the visit command, they're discarded when the redirection takes effect (it's from a different domain)
i'm stumped. anyone has a way to address this?