It’s a progressive tax, tied to the federal income tax. Do your 1040, then transfer your AGI to line 1 of the AZ tax form.
I’ve never paid much attention to the actual tax rate; I think it starts around 15% and goes up from there.
Hopefully, it isn’t that high. 15% would be astonomical unless there would all kinds of deductions for middle income earners to bring it down to around the 5% range.