Firstly, for supplier and employee records make sure that you have their bank account details populated in the bank details tab.
The key elements are that you have your own bank details input into the bank ledger account (click the spanner icon) together with the APCA number and the Include balance record ticked (unless your bank has advised otherwise)
When making a payment, select direct deposit as your payment method then head into Bank Payments. Complete the payment and then click on Bank Payments and create a new ABA file by clicking Add then click on Add Payment items button and select the payments you want to include in this ABA file. When all are added, select Generate File and this download a copy of the ABA file. Save it to a convenient location and upload it to your bank.