I am trying to open an assignment directly from URL link using "pyMobileSnapStart". I have created a SupportRequest work item (Class: MyCo-MyApp-Work-SupportRequest), and it is not resolved yet (assigned to someone's Worklist). pzInsKey is "MYCO-MYAPP-WORK S-1".
I found out what was wrong. pzInsKey in Assign- class includes flow name at the end. So I had to type my own flow name "APPROVE_FLOW" instead of "OPEN". "OPEN" is just an example for Help document. In my case, when I enter below string it worked.