How can I get back to the screen where I can go through the questionnaire on whether or not to itemize deductions? I chose standard deduction and can't reverse that.

I can't find a way to return to the start of the deductions and credits screen. I inadvertently chose "Proceed with Standard Deduction" and can't undo that. The app seems convinced that standard deduction is the best option and will not let me change that even though I haven't entered any deduction information for it to base that on. This appears to be a bug in the app.