The integration with your finance software (Sage Accounting, Xero or QuickBooks Online) will involve all accounts from your chart of accounts pulling through into your Futrli account. This will include any accounts with zero values.
Rather than displaying all accounts in a forecast, the default view will be for any account with zero value to be hidden. This however can be easily updated.
In any Futrli forecast, you will have a controls option in the top left of the window.
You will then see the option to Show unused accounts. Give that a click and your forecast will update.