Hello Bala,
Thanks for posting!
As per my research on this, the actual URLs for downloading usage reports can vary depending on the specific report you are trying to download and the service you are using within Azure. These download URLs needs whitelisting in your network proxy for accessing the reports. The URL 'https://reports.office.com/data/download/<report-id> covers the Office 365 service regions. Note that here <report-id> should be replaced with the unique identifier for the report you are trying to download.
The URLs you mentioned appear to be specific to the Microsoft 365 service regions. The 'reportssea.office.com/data/download/<report-id>' and 'reportsweu.office.com/data/download/<report-id>' are used to download usage reports from the Microsoft 365 admin center for customers in the Southeast Asia region and Western Europe region respectively.
Microsoft provides documentation that includes information about various Office 365 reports available, but per my research, there is no documentation available with comprehensive list of URLs for all Office 365 reports for all types of Azure environment tenants.
Hope this helps.
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