To add the ATO as a Bpay payee, you will need to head to the Payees tab from the left hand-side of your dashboard.
1) Select Add Payee > BPay
2) Enter the details on the following pop-up window
3) In the ABN and business name field, type in Australian Taxation Office, and select the option that does not include Superannuation
4) Once all details are entered, select Add Payee. This will save the ATO under your BPay payees in your account