I am having the same issue. I spoke to Shopify via live chat. They told me that it is out of there hands because I have a red flag up on my business manager account because I changed my business name and wanted to change it with my business manager as well. Now I cannot create or add a new ad account. The person at Shopify told me to get a hold of facebook, that they have some live chat support or something. The don't. i can't get a hold of them. I made my first sell the other day, but now I'm losing people views and sessions through my store because I can't create campaigns with my facebook ads account via Shopify store. What a barrier.