The problem is bigger than that and here you are the details:
I purchased the ArcGIS for Personal use two days ago, then I received an email from Esri with a link to My Esri website, and when I clicked on it, it took me to my purchase details, one of them was about ArcGIS Online subscription and 100 credits with a big blue button labeled by Activate. What happened next is that I clicked on that button and it took me to the ArcGIS Online login page, I had two options, option one is to create a new account and option two is to use an existing account. However I used my existing Esri Account (public ArcGIS Online account) and I thought it will be upgraded from public account to a named user account (which can be used to open ArcGIS Pro. And publish map service to ArcGIS Online).
The problem now is that my Esri public account did not upgrade to a named user account and when I go back to My Esri website it tells me that my ArcGIS Online subscription is Activated !!!!
What I want from you is to tell me where/how I can find my named user ArcGIS Online Account???