Unfortunately, this app has no feature for restoring deleted entries.
If you absolutely need to recover one, and your device itself was backed up with iCloud Backup before the deletion, you may be able to restore your device to that earlier state.
The method is described below. It erases the entire device, so other data and apps may be lost. We cannot guarantee the result in any way. Please proceed at your own risk.
First, open the Settings app, tap your name at the top (your Apple Account), then tap "iCloud".
Next, tap "iCloud Backup". Devices with iCloud Backup turned on are listed there. Tap your device to see the date and time of the last backup and the list of apps whose data is included in it.
If this app is in that list, its data as of that date is included in the backup.
If you want to go back to that data, you can restore your iPhone to that backup, which brings the whole device back to that point in time.
To erase the device, open the Settings app, tap "General", tap "Transfer or Reset iPhone", and then tap "Erase All Content and Settings".
A message may appear asking whether you want to update the backup before erasing. If you update the backup at this point, it will overwrite the backup with the current state, in which the entry is already deleted. Do not update it; continue to the erase step instead.
Afterwards, when you set up the device again, choose to restore from the iCloud backup, and the device will return to its earlier state.
Once again, erasing the device carries risks: other apps' data may be lost, and unexpected problems may occur. We are unable to provide support for the device erase procedure itself. Please treat this only as a reference and proceed at your own discretion.