Messenger ID Mapping API returns empty data

I want to get the real facebook id of users who interact with my messaging app using this . When I debug using the graphical api explorer I get results if I use my own psid returned by the messenger to send the request, but if I use the psid of other users it gives me an empty array of data. What could be causing the problem?

GET / {my-own-psid} / ids_for_apps - Returns the result

GET / {other-users-psid} / ids_for_apps - no result