IMDB pro for my 2 kids without creating 2 new Amazon accounts for them

Hello, I've registered IMDBpro on my name using my Amazon account. It was very new for me, I used it for 3- days trial and shut down the membership. I have 2 kids who are aspiring actors and they are about to receive credits... I don't understand how can I make 2 IMDB pro accounts for them without creating 2 Amazon accounts for my kids (it does not make any sense, they are too small to have them)... Thank you, I'm about to give up, I will appreciate any help.