Unable to deploy addin from Office 365 Admin console using URL

[mkondadg]

Unable to deploy addin from cloud hosted URL below
https://cdn.fortra.com/digitalguardian/agent/outlook-addin/v1/manifest.xml

But if deployed from https://s3.amazonaws.com/cdn.staging.fortra.com/digitalguardian/agent/outlook-addin/v1/manifest.xml, it works properly.

Your Environment

PC Desktop
Microsoft Outlook

Expected behavior

Able to deploy Addin from Office 365 admin console

Current behavior

Unable to deploy the addin

Based on cloud logs, it seems Microsoft is not providing "User-Agent" headers which is causing this issue.

Steps to reproduce

1. Login to Office 365 admin console
2. navigate to above url and deploy the addin

Context

Unable to test locally and customers cannot deploy the addin.