No. A tutor cannot host a private session meant exclusively for one learner. While tutors can still host a session if only one learner shows up, tutors cannot intentionally exclude other learners. All sessions have to be publicly available for safety and accessibility reasons.
If you are planning a session for a specific learner, please add a detailed description of what you plan to cover in the description so other learners can join if it's relevant to them.
For more information why this policy is in place, check out this article.