Basically, the system will calculate VAT once there are sales transactions recorded. Thus, separating them need to be done manually. I'll guide you on how.
To get started, you can either record a bank transfer or create a journal entry to move the VAT amounts to the account you need. Here's how:
Go to the +New icon, then select Journal Entry.
Fill in the information, then select the account under the Debit and Credit column.
Save the transaction.
Before separating the amounts, I would recommend seeking assistance from your professional accountant. An accountant can assist you with choosing the correct accounts for journal entries to keep your books accurate.