I should structure the blog post to first clarify that Norton 360 Mobile might not require a product key but instead uses the user's account. Then provide steps for activation, how to retrieve or share the product key (if applicable), and tips for managing the subscription. It's also important to mention the support resources in case the user needs further assistance.
I should confirm the process. Let me recall: many security apps for mobile now use account-based licensing. So instead of entering a product key on the phone, you download the app from the app store, sign in with your Norton account, and the subscription syncs automatically. That could be the case for Norton Mobile Security.
Another angle is that the product key is a digital license that's managed through the Norton account. When you renew your subscription, you don't need to enter the key again. For mobile apps, the activation is automatic if logged into the same account. So perhaps the user is looking for instructions on how to manage their license or troubleshoot activation issues on their mobile device.