Use this endpoint to create or update user records, using a unique attribute to search for existing users (for example the primary_email_address attribute). If a user is found with the same value for the matching attribute, that user will be updated, otherwise a new user will be created instead. If the matching attribute is a multiselect attribute, new values will be added and existing values will not be deleted. For any other multiselect attribute, all values will be either created or deleted as necessary to match the list of supplied values.

Required scopes: record_permission:read-write, object_configuration:read.