You can always go back to Arizona after the review. Click Continue on the Ready to Review and complete the review. Then click Your State Returns at the top. Then Edit next to Arizona.

Thanks for your reply.  That has always worked in previous years but, strangely, not this year.  The only way to do it is to choose the step-by-step menu on the top right, go into that menu and then choose the step you need to amend.  Then continue from there.............