VSTO Publisher Info None when signing using this tool with AzureKeyVault certificate

our primary goal is to ensure our Office Add-ins display “Your Company” as the verified publisher within the Office Trust Center, rather than showing “None” or “Unknown Publisher.” <img width="840" height="687" alt="Image" src="https://github.com/user-attachments/assets/5f7f4b09-6abf-4bd8-b2bf-8ff065547edb" /> We have cloud-based code signing solution and DigiCert EV Code Signing Certificate issued by Digicert. This is stored in our Azure subscription under keyvault resource (attached screenshot). When we download certificate only public cert is downloaded without any private key. <img width="1200" height="142" alt="Image" src="https://github.com/user-attachments/assets/35601b23-4230-4057-bdef-0b0a4b75a1a3" /> <img width="800" height="702" alt="Image" src="https://github.com/user-attachments/assets/39da9103-afb3-41e4-852d-e813dfac9e0b" /> Was not able to sign VSTO Addin using Sign tool/Mage/AzureSignTool exe but was was able to sign Addin using tool. but Publisher info is coming as None. Am I missing anything or is it issue with certificate? Thanks and Regards, Rakesh Khullar