Ran into this issue this past summer hopping around the islands:
You’ll need to go to a ticket counter to get on the list for the jumpseat. Simply going to the gate does not work.
So- like what others have said, this means you’ll want to show up earlier than you’ve planned for a flight.
For example- KOA-HNL. It took me all of the 1:15 prior to departure time for me to wait in line at the ticket counter to list, then wait in line to go through security, and then check in at the gate.
The issue is there are no check-in kiosks for passengers (everyone must see the ticket agent), and there are no KCM or TSA precheck lines for security. Also, nearly everyone is a tourist, so expect slow progress through the metal detector.
But, with that all said, the HAL flight and cabin crews are very nice and welcoming. Class act all the way.