Facebook Ads Manager is a Facebook tool where you can create and manage your Facebook ads. On the Ads Manager, you can: See: How To Turn on Notifications on Facebook
According to the Facebook Help Center, if you manage multiple ad accounts on Facebook, you can use the Account drop-down menu in Ads Manager to go to another ad account.
Tip: You can view all ad accounts and Pages you manage in Facebook Business Manager.
How to Switch between Facebook Ad Accounts
To switch between FB ad accounts, do this;
1. You’ll need to go to Facebook Ads Manager.
2. Next, click the Account drop-down menu.
3. Finally, choose the ad account.
That is how to switch between Facebook ad accounts. How to report a problem with Facebook | Step by step