You can manually input your balance by going into the Chart of Accounts, Fiona.
Before doing so, did you encounter any error message when trying to link your bank to QuickBooks? This distinction will help us understand the issue and deliver a suitable solution.
Here's how to manually add:
Navigate to Transactions and choose Chart of Accounts.
Locate the account you wish to review. If you are new to QuickBooks.
Select See your Chart of Accounts. From the Actions column, select Account History.