WordPress does not track that information. You can’t find it because it does not exist.
Unless you specifically wrote code to track when post meta was added/modified, that information doesn’t exist, and it’s rare that any plugin would implement this as it would result in a lot of data collection.
It would also be obvious where that data was when looking at the database via PHPMyAdmin, which I and yourself did not see in the screenshot. So this data was never recorded, does not exist, and cannot be used. It would be a fools errand to continue the search.
The best hope you have is to check backups of your site and compare them by date to get a rough estimate of how far back the data existed. Emails/receipts/invoices might also corroborate this, but nothing in WordPress exists to tell you when a post meta was created or last modified.
The only other thing, is the post creation date, the post meta creation date must be the same or newer, but not older.