Hello Gokhan,
We can do it on native iOS and Android as the platform provides some time to save data before sending Application in the background mode but the same thing is not possible in case of force close. In Unity, the MonoBehaviour class have some APIs like OnApplicationPause / Quit which you can use. But it may behave differently on different platforms.
You can also post this query to Unity Community to get more idea to solve this problem. I would recommend you to cache the data and send it to server immediately after you have this data instead of waiting for application close.
Let me know if you have any further queries, I will be happy to help you.
Regards,
Rajeev