I need to check details of an old (lost) credit card from my mSecure backups (2019) on my Mac. How do I 'open' a particular backup to try and 'look' at the old credit card details?
In order to view older backup files, you would need to restore the data that is in the backup. The problem is when you restore data, you overwrite the data currently stored in the app. In order to go through this process without loosing any of your current data, you would need to create a brand new backup of your information, restore the data from the old backup file to get the old Credit Card data, then restore from the new backup file you just created.
Alternatively, if you have multiple devices running mSecure and syncing your information, you could turn off syncing, then restore from the old backup on your Mac. This would give you access to the old Credit Card information. After you were done getting the old data, then you could delete the database file on your Mac, sign back in to your account and turn syncing back on. This has the benefit of always having access to your current data on your other devices. Either way, however, you would want to create a brand new backup in case something goes wrong.
Do those options make sense?