Anta is the Arabic pronoun for "You" (masculine singular). It is direct, personal, and immediate. It does not refer to "him," "her," or "them." It addresses the subject directly in the second person.
Think of it as a paradox: "To be yourself, you must become that person." It is a call to shed pretense, discard societal performance, and return to an authentic, divinely-guided nature (Fitra). Kun Anta