Answers

It appears that you are missing both step flashing (between the roof and the wall) and the head flashing (above the trim running parallel to the roof line). Here is the link to the Hardie Best Practices manual with specs on both flashings: https://www.jameshardiepros.com/getattachment/9a1017e1-853d-4574-b3e9-7afb1a5a472d/intro-tools-hz5-us-en.pdf.