To maintain consistency, make sure the UPN matches for both your on-premises AD and Azure AD accounts.
Cloud services only recognize accounts that exist within Azure AD. If an account exists only in your on-premises AD, it will not be usable.
There are different ways to align your on-premises AD accounts with Azure AD.
Add accounts manually to Azure AD
Create an account on the Azure portal or within the Microsoft 365 admin center. Make sure the account name matches the UPN of the on-premises AD account.
Use the Azure AD Connect tool to synchronize local accounts to your Azure AD tenant
The Azure AD Connect tool provides options for directory synchronization and authentication setup. These options include password hash sync, pass-through authentication, and federation. If you’re not a tenant admin or a local domain admin, contact your IT admin to get Azure AD Connect configured.
Azure AD Connect ensures that your Azure AD UPN matches your local AD UPN. This matching helps if you’re using Analysis Services live connections with Power BI or single sign-on (SSO) capabilities.