Usage This setting is used to determine whether a user is an Office 365 / Azure AD user in your organizational directory or not e.g. when a user attempts to sign into your website manually, change his or her email address or password or when the plugin tries to retrieve an Office 365 profile image instead of the WordPress avatar (depending on the installed plugin edition).
To see your custom domains you can navigate to the Azure Portal Azure Active Directory Custom domain names.
To support enterprises that have mapped multiple domains to their Office 365 tenant, you can add more than one custom domain. Also add the default domain that ends with onmicrosoft.com to the list of custom domains.
Important After you entered a domain name in the input box you must click “+” to add it. This is also true when you are entering just one domain.
Default value empty.
Visit the website https://www.wpo365.com/