Multiple children with IMDB accounts how to renew through Amazon

I have 3 children with IMDB accounts.  2 have current IMDb pro accounts, and one is currently just IMDb because I have been unable to renew her IMDB pro account  because it keeps taking me to amazon, which is linked to my son's IMDb pro account, so I am unable to renew for my daughter through my son's account.

How do I renew my daughter's IMDB pro account?