Conditional Access is a capability of Azure Active Directory that can be used to enhance the security of organizations in the Microsoft cloud.
Your customers can use Conditional Access with this limitation: The Global Administrator directory role must not be included in blocking rules of Conditional Access policies because this will break the integration between the application and the Microsoft cloud.
To learn more about Azure Active Directory (Azure AD) Conditional Access, see https://docs.microsoft.com/en-us/azure/active-directory/conditional-access/overview.