There have been numerous posts online regarding iPassword no longer working with the latest iOS update. I was able to transfer all the passwords from this non-working iPassword app to the new version of iPassword that does work with iOS 14.5.
For brevity I will refer to things as old phone old app and new phone new app where the old phone has pre-iOS 14.5 and the working old app and the new phone iOS 14.5 has a non-working old app and a working new iPassword with no data.

Required:
* You MUST have an iPhone with pre-iOS 14.5 where iPassword still works. You can still download old iPassword onto that phone whether it is your own or a borrowed one. I borrowed one and downloaded the old app version of iPassword from the Canadian App store. I did see it in the US App store but I was on my new phone so it wouldnâ  t download on that.
* You MUST have your master password for your existing old App. Finger print access is not enough.
* You MUST have the new version of iPassword that works with iOS 14.5.
* You need a 3rd party software that can read all the details in your iPhone. Someone recommended iMazing that can be downloaded from imazing.com. The trial version is all you need but I purchased it out of gratitude for saving me a lot of work finding and re-entering hundreds of passwords and other data.
* You MUST have iTunes on a PC or Mac

The following steps are for a PC. The Mac works similar but the screen details in iMazing are a bit different on the PC than on the Mac. iMazing on-line tutorials are good for the Mac but not so good if you are a PC user.

Step A: (Back-up most current old app data on current new iPhone)
* Install iMazing to your computer and connect your New Phone that has the old app to the computer.
* Start iMazing, Click on your New Phone in the â  Available windowâ   on the far left.
* Click â  Manage Appsâ   from the selections available to the right of all the apps that are displayed.
* Scroll to old iPassword and right click on it.
* On the right click menu select â  backup App dataâ  
* Selection Destination where you can find this file. Leave â  Back Up and Extractâ ¦â   selected.
* Click â  nextâ  , then â  okâ  

Step B: (Restore most current old app data to old iPhone)
* Connect Old phone to your computer
* Click on your Old phone in the Available Window on the far left
* Click â  Manage Appsâ   from the selections available to the right of all the apps that are displayed.
* Scroll to old iPassword and right click on it.
* On the right click menu select â  Restore App dataâ  
* Click â  Chooseâ   and select the folder where you saved your old app data in Step A.
The file you should see is â  iPassword.imazingapp
* Click â  Doneâ   and follow the next steps on the screen.
* You should be able to open the old app and all your current data should be in there.
* You can manually enter this data into a new password manager or follow the next steps to restore this data to the new iPassword app on your current new iPhone

Step C: (Back-up your old phone iPassword with updated data to iTunes) I find iTunes difficult to use so my steps may not be the best way to do this but this is what I did.
* Start iTunes and connect your old phone to your computer.
* Click on the phone icon that is right below Controls and Account on the menu bar. Do not Click the one below devices on the far Left window.
* Click on File Sharing in window on far left
* Scroll the Apps window and select old iPassword. There will be nothing in the Right window under iPassword Documents
* Open iPassword on old phone and go to settings.
* Scroll down to â  Backup & Restoreâ  
* Select via â  iTunesâ   Other methods may work but pay attention to the next steps first.
* This is where you need your Master Password
* Select Backup. This will create a backup in iTunes in â  transfer sharingâ   DO NOT exit the iPassword window on your phone yet. If you do, the back up in iTunes will be deleted.
* The file in the iTunes transfer sharing folder is called â  iPassword_2021_06_22.backupâ  . The date being the date you created this backup. You must copy this file to someplace else fairly quickly because iPassword automatically deletes it after a short time period even if you donâ  t exit the app on your phone. I found I have to drag the file to and from the desk top or another folder. I couldnâ  t see a way to copy and paste.

Step D: (Restore iTunes â  iPassword (date).backupâ   to your new phone new iPassword app
* Attach new phone to your computer
* Click on the phone icon that is right below Controls and Account on the menu bar. Do not Click the one below devices on the far Left window.
* Click on File Sharing in window on far left
* Scroll the Apps window and select new iPassword. There will be nothing in the Right window under iPassword documents
* Drag the â  iPassword (date).backupâ   from where you saved it into the file sharing folder
* Open new iPassword on New phone and go to settings.
* Scroll down to â  Backup & Restoreâ  
* Select restore
* Click â  continueâ   
* If successful the Password will be from the old App data not the password you created when you installed the new iPassword.

I stepped through the process as I was typing this so if it doesnâ  t work for you, you likely missed a step or didnâ  t follow the instructions accurately. Try again. It took me a few tries to get it to work the first time.