Lightning: Recovering Deleted Items From Recycle Bin
If you've accidentally deleted a record, for a period of time, you can still recover it from the Recycle Bin.
Deleted records remain in the recycle bin for 15 days, and can be restored during that time.
Click the App Launcher icon
Search "Recycle Bin"
Click Recycle Bin
Select a View
Check the file to undelete
Click Restore