Never assume internet connectivity. Your wizard must detect network loss and instantly offer the offline/phone method. Do not hide it in a submenu.
If you don't have internet, you can select the "automated phone system" option. The wizard will give you an Installation ID to read over the phone, and you'll get a Confirmation ID to type back into the wizard. Stopping Pop-ups: product activation wizard
: A wizard that launches when you select "Activate a product on Steam," requiring you to agree to terms and enter a CD key or product code. Never assume internet connectivity
[Your Name/Role] Approved By: [Product Owner / Engineering Lead] product activation wizard