How to create an Identity Protection PIN for my minor child?

Several people have asked this question, but I don’t actually see the answer.  How can I voluntarily create an identity protection PIN for my child?

 

I already have an IRS online account.  I am looking at the IRS online website, but I do not see any way to create an IP PIN for my wife or child.  Is it possible to do it online?  Do we need to create a separate IRS online account for my wife, and another IRS online account for my minor child?