Hello leonadooher,
You can create an expense posting to the creditor's account which can then be applied to a future bill payment once the bill is received and entered on QuickBooks.
To do this, go to the Supplier and select New transaction > Expense. On the 'Category' drop-down, select the 'Creditors' account and enter the amount and additional details. Once saved this will appear on the suppliers account as an unapplied credit.
Once you have raised the bill and are ready to make payment, you can apply the expense by selecting 'Make Payment' on the bill - the expense will then show under 'Credits' - tick to apply to the payment and save.
Thanks