Currently, it's impossible to get a list of unique test cases written by a specific user via the API because this list also includes cloned test cases. For example, if a user wrote 10 test cases and cloned 20 from another project, a search for the number of test cases they created using the "createdBy" field will show 30 test cases in the list. The goal is to obtain only the unique, originally created (not cloned) test cases.