Facebook requires you to turn two-factor authentication, the security feature for Business Manager on. If you have not turned it on, your ad accounts will be restricted and this stops you from creating and running ads. Once you turn it on you will be able to create your campaigns.
1. The Ad Accounts at your Business Settings will display that Facebook restricted it.
2. Go to Business Settings and click on Business Info.
3. Below Two-Factor Authentication at Business Options, choose Required for everyone or Required for Admins only.
4. Then, click on the link below Security at My Info to set up your security method and log in.
You can also click on the following link to learn more about it: https://www.facebook.com/business/help/280940009201586