You have to use “Empty Instrument” instead of “New instrument”.
borsaitaliana is not automatically readable for PP, but here is an attempt at an explanation of how to manually get historical quotes from there: How can I track certificates? - #2 by ProgFriese
Another possibility is investing.com, there you can get historical quotes for some securities.
Example: https://de.investing.com/rates-bonds/btp-tf-3,85-st49-eur-historical-data
If you don’t care if the quotes come from Milan, there are other possibilities, e.g. onvista, but there only for German stock exchanges, therefore with less volume.