If a participant links to our poll (that uses Facebook SSO) from their Facebook account (that they are already sign-in to) do they need to re-enter their Facebook credentials to access the poll. i.e. can credentials be passed from Facebook to PollUnit?
PollUnit cannot access or reuse an existing Facebook session directly.
When a participant opens a PollUnit poll that uses Facebook Single Sign-On, they must initiate the Facebook login flow on the PollUnit page. PollUnit does not receive Facebook credentials, nor can credentials or sessions be passed from Facebook to PollUnit automatically.
During this process, Facebook may recognize that the user is already logged in to Facebook and therefore may not require them to re-enter their username and password. However, the authentication step itself must always be explicitly triggered via the Facebook SSO interface on the PollUnit page.
PollUnit only receives an authentication token from Facebook after the user has successfully completed this login flow. The exact login experience (e.g. whether Facebook asks for credentials or just confirmation) is fully controlled by Facebook.