SharePoint Admin Center classic reports are traditional SharePoint reports. To view these reports, follow these steps:

1. Navigate to the SharePoint Admin Center (https://admin.microsoft.com | Admin centers | SharePoint | Classic features) and select Open under Search.
2. On the Search Administration page, select View Usage Reports.

3. Click the link for the report you wish to retrieve. A list of available reports can be seen in the following screenshot:

Reports are generated and downloadable in Microsoft Excel format.