Hi there,
You'll need to access the Win32 API to interact with the Credential.SecretManagement and SecretStore from Microsoft appear to be the official solution.This module provides a convenient way for a user to store and retrieve secrets. The secrets are stored in registered extension vaults
I came across these articles which try adding certificates on credentials manager using Powershell.
PowerShell support for certificate credentials
https://devblogs.microsoft.com/scripting/powershell-support-for-certificate-credentials/
Certificate-Based Credential via PowerShell
https://social.technet.microsoft.com/Forums/windows/en-US/cf568114-7aa1-4c55-8755-9740f0e8827d/certificatebased-credential-via-powershell?forum=win10itprosecurity
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