I know how important it is to undo a deleted transaction, Jarm.

In QuickBooks Online, there isn't an option to undo a deleted transaction. Restoring it may create discrepancies that you have to fix. Not to worry, you can use the Audit Log to recover the details and manually re-enter it.

Here's how:

1. Go to the Gear icon and then select Audit Log.
2. From the Filter drop-down menu, select the appropriate user, date, and event(s).
3. Select Apply.
4. Locate the deleted transaction. 
5. Under the History column, select View.
6. All the information needed for the transaction can be found under the Event column.
7. Using the information from the Audit log, re-enter the transaction with its original transaction date.

To add this option in the future, I'd recommend sending a feature request directly to our Product Development team. This helps us improve your experience with the program. Here's how:

1. Go to the Gear menu and then select Feedback.
2. Type in your feature request in the description box.
3. Once done, click on Next.

If you want to remove a transaction in the future, I'd suggest voiding it. This way, you can keep a record of the transaction.

I'll be right here to help if there's anything else you need. Have a great day!