You're likely right. Epic FHIR R4 API usually doesn't have a direct Create endpoint for Encounter. Encounters are typically created automatically by Epic's internal workflows (like appointment check-in).
For integration:
Interact with related resources (like Appointment).
Monitor their status.
Use FHIR Search to find the created Encounter.
Check your specific Epic documentation and consult healthcare IT experts for definitive answers, as custom implementations might vary.