Hi @agnes-hsq and thanks for your query. The Tobii 4C is designed for interaction and gaming purposes primarily with the associated SDK also created for this purpose.
The use of the 4C for Analysis or Research (The storing of gaze data in any form) requires the purchase of the analytical use licence.
You can read more about this @ https://analyticaluse.tobii.com/overview/#analytical-use
Sorry for the unfortunate news, but this would also apply to the visualisation of a gaze path that would necessitate gaze data storage.