Many organizations don’t use LDAP or active directory for user authentication. In other scenarios, some users are not in LDAP and are created only in ThoughtSpot. In such cases, you can choose to authenticate users against ThoughtSpot internal authentication.
If you have been using ThoughtSpot with users you created manually, and you now want to transition to LDAP, contact ThoughtSpot Support. They can assist you in migrating existing users to their LDAP equivalents.