How to add a comment with rich text (text+images) to the work item (task) with Powershell

Hi All,

I am trying to add a comment into discussion and other custom fields based of rich text programmatically (using PowerShell). Can you please guide me how to upload the image. I browsed online and able to send the text using REST API calls and AZ CLI cmdlets but how to upload images. Can you please provide some docs. or example reference. Thanks in advance!