If you're getting a popup inside of QBs, it sounds like your system has been hacked!!!
Did you have some Support work done in the past? It sounds like you may have not been using Intuit/QBs even though you thought you were.
I would make a backup of your Company Data Folder, but then you need to get to the real QuickBooks Support. I would assume they modified your User Interface if the popup is really coming up in QBs, so that means they may have changed the Help phone numbers and link to Support. I'll put in the link below for reference, but I'd go research it for yourself on a different computer. What I want you to see is the "intuit.com" and how it is spelled. Be very careful of sites that look similar.
Hopefully @Adrian_A(note the "Admin") or one of the other Intuit people that have "Employee" after their name will chime in to confirm the website.
https://www.intuit.com/support/
