Every account starts by signing in with Google or GitLab - see Concepts › Single sign-on. Beyond that starting point, your organization can connect its own identity provider through a self-service setup wizard at Settings › Identity Provider - see Configuration › Single sign-on for how.
Supported providers#
Directly, by name: Microsoft Entra ID, Okta, Google Workspace, Active Directory, Auth0, AWS, CyberArk, JumpCloud, OneLogin, Oracle Cloud Infrastructure, PingOne, Duo, Salesforce, LastPass, and Cloudflare.

Anything not on that list connects through a generic SAML, OpenID, or LDAP integration instead.