Policy1 is defined at the Tenant Root Group with the Category set to Monitoring. To have resources noncompliant with Policy1 appear in the Microsoft Defender for Cloud / Security Center dashboard, what should you do first?

To have non-compliant resources appear in Microsoft Defender for Cloud (formerly Security Center), the Azure Policy must be part of an initiative that is specifically integrated with Defender for Cloud. Simply defining a policy with a 'Monitoring' category or assigning it directly won't achieve this integration. By adding Policy1 to a custom initiative, you can then onboard that initiative into Defender for Cloud, allowing its compliance status to be reflected in the dashboard. Changing the category to 'Security Center' is not a valid policy category and won't enable the integration. Changing the definition location or assigning it to a subscription doesn't inherently link it to Defender for Cloud's compliance reporting.