You're correct: the Import function cannot (currently) connect a requirement in the list to another requirement in the list as a parent/child, because the parent still doesn't have an ID and will have it only after it's created in PractiTest.
We have a request to enable such a functionality in our Feedback forum, and I highly recommend to upvote it - the more upvotes each request gets, the higher it stands in the priority list of our Product Team for implementation. You can find the request here: https://practitest.uservoice.com/forums/27423-general/suggestions/20424178-import-jira-requirement-ticket-with-all-it-s-sub-t, feel free to add your comments as well.
Meanwhile, I can offer a solution to update the Requirements with the Parent IDs via our API.
One of the many options our API provides is an ability to update Requirements' fields values, one of them can be Parent ID.
So the order of actions should be as follows:
1. Import the whole list of Requirements;
2. Apply the GET request on the imported Requirements: https://www.practitest.com/api-v2/#get-all-requirements-in-your-project
(if these aren't the only Requirements in the project, you can create a Filter which will contain only those you imported - for example, per Created Date Criteria, and use this Filter as a parameter). Retrieve the IDs of Requirements from there:
3. Apply PUT requests on Requirements which supposed to have Parents per their IDs: https://www.practitest.com/api-v2/#update-a-specific-requirement
Another solution you might consider (though I assumed you considered that already):
1. Import only Requirements that do not have Parents;
2. Create a Report (for example, Tabular Summary Report) for the newly imported Requirements, where you can retrieve their IDs
3. Import the remaining Requirements, filling the Parent column with respective ID of each parent.
I can elaborate on both solutions, if any of the steps is unclear.
Please let me know if it helped!
Alex from PractiTest team.
P.S. For more questions, and adjustments of our product to your specific use case, I'd highly recommend to schedule a demo session with our Customer Success Manager, you can do it via this link: https://calendly.com/practitest/practitest-demo-session?month=2021-07