As long as you've entered all your data and you've checked the GST on each transaction you can create a BAS Statement that is compliant with the ATO. It's always good to get someone to glance over it or create the Statement for you, so you may choose to engage your Accountant at this point.
The process is as follows:
Make sure all your transactions have been recorded for the quarter.
Go to the LEFT HAND side Menu
Find the REPORTS Icon
Select GST REPORT
The BAS Report will appear.
Look at the QUARTER you are doing at the moment and make sure the correct Quarter is selected.
Answer the question on Private Usage, it's default is YES, but most business will need to select NO, then click continue
Run down the list of Expenses and change the Business use if that Expense item was used for private purposes
Select Continue
Check the paranters and click CONTINUE
Your BAS statement should now be complete. You may need to add amounts at T1 and T2
Log into your MyGov account and replicate the BAS Statement there.