If your SSO configuration is enforced, Algolia restricts the authentication methods - so it's not possible for selected users to bypass the SSO and log in using another method.
For contractors and external users, it is often possible to provide them an email address with a suffix like '.ext@my-company.com' so we can add this to the list of domains in your configuration.
It can be an email address just used for SAML access, the email address doesn't have to be valid.