The publishing of IntelliTect.Snippets to the Visual Studio Marketplace is done through its associated DevOps pipeline.
The pipeline yaml script runs whenever Master is updated. It build the IntelliTect.Snippets solution and then has a PublishVisualStudioExtension@3 task (See Azure DevOps Extension Tasks). This task requires that the IntelliTect.Snippets azure project has access to a Visual Studio Marketplace Service Connection (Found in Project Settings -> Service Connections).
The service connection then requires a PAT created at the Organization (IntelliTect) level.
How to create an Azure PAT for Visual Studio marketplace
**If the publishing task is failing, check to see if the PAT has expired **
The Associated Visual Studio Marketplace Publisher ID is IntelliTect