Hey there, @ddd23123123, sorry to hear about that!
If the app wasn't syncing, that means that whatever changes you made locally never synced to our servers.
Usually, when you re-install, what should happen is that the changes you made should sync online, but in some rare cases, the opposite happens. This seems to be the case.
Therefore, there wouldn't be something for you to restore. I suggest taking a closer look at your events page, just to confirm when the last edit took place, and see if you can find anything more.
Keep me posted!