It's not possible to help you with such a generic description of the problem.
In order to see passengers, the scenery must have either:
- A least one GSX/SODE jetway that has been docked.
OR
- A SODE jetway provided by the scenery that has been docked
OR
- If the parking is not a gate with a jetway, stairs and a passenger bus must come
In addition to that, the airplane payload (not fuel, the payload ) should be correctly BEFORE calling GSX.