I just recently dealt with two clients with this issue.  I completed page one and three of the 500-NOL.  Client and I signed page two (filled in the preparer info as well) and then uploaded this form and a copy of the 2019 federal return with all schedules and NOL worksheets included to GTC. I also got power of attorney and uploaded to GTC as well.  Gave it a day and then called the general individual income tax line (takes forever) and then asked for the NOL department.  After another wait, the agent reviewed the forms and that was that... Good luck.