Hi there, @cresa. Let me give insights regarding importing the backup file you sent to your accountant inside QuickBooks Desktop.
In your case, since you don't have any backup files saved, please note that there's no way to import your lost data. You can't import the accountant's copy that you have because you can only restore a QBB file in QBDT, as it is the extension of QBDT backup.
To prevent this from happening in the future, you should regularly save a backup file to ensure you have a safe copy of your account data within QBDT. You may have a cloud backup or an external drive to ensure you have a secondary method of retrieving any data.
On the other hand, to share your accounting data or move it to another computer, you can check this link for a guide: Create and open portable company files in QuickBooks Desktop.
Keep us posted if you need further assistance importing a data file in QBDT. I'm here to help. Keep safe.
