For collaboration purposes, you may want to add more users who can make changes to your Masthead. To do so, start by navigating to Manage Organization from the Masthead homepage. This will take you to a page where you can view your billing information, add administrators and update your contact info.
Adding a Masthead Administrator
From the Manage Organization page, navigate to the Administrators tab.
Here, click Add New to add the UPN of a new administrator. Once you’ve done this, they’ll be given administrative access to your Masthead.
What is a UPN?
A User Principal Name (UPN) is an authentication method. It typically uses the name of a system user, followed by the desired website domain. Microsoft Office 365 provides you with a unique, Office 365-specific UPN that you can find in Office 365 Admin Center. You can view your UPN under the Domains tab. To add new Administrators, you will need to know their UPN found in this location.