Just look amog the results, it seems you are capturing the data, the issue is that you are not looking in the proper request but the credentials should be captured.
Can I see the result of ifconfig in Kali, ipconfig in the target machine, bettercap’s version, the command you used to start bettercap and the contents of the spoof caplet please?
Can you also show me Kali’s and Window’s network settings, so just right click the Kali machine from Virtual box >> Settings ?? Network, take a screenshot and post it here please.