It looks like Microsoft has recently updated security or permissions policies for triggering Fabric pipelines via the API, which may be causing the "Forbidden" error you're now seeing. This issue can often occur due to:

• Permission changes: The service principal or user account previously used for the API call may no longer have the necessary permissions or roles.

• Authentication issues: Token expiration or updated scope requirements can result in access being blocked.

• Changes to API requirements: Microsoft sometimes updates REST API endpoints or the way authentication works, which may require modifications to Power Automate or any custom logic.

Recommended steps:

• Double-check the permissions for the service principal or user in the Azure portal and ensure the correct roles are assigned for both the workspace and pipeline execution.

• Review any recent Microsoft Fabric documentation or announcements for changes related to API authentication or permissions.

• Try manually triggering the pipeline API call using Postman or a similar tool to isolate whether the issue is with Power Automate or the API itself.

• Confirm that your authentication tokens include the required scopes for the Fabric API.