Any version of the server can be configured to use Virtual Directory. By default, Azure DevOps Server 2019 uses empty Virtual Directory (VirtualDirectory="/") while previous versions of the server used /tfs as the default.
To find out the value of Virtual Directory for your server check the server configuration as follows:
Open Azure DevOps Server Administration Console from start menu and navigate to Application Tier. The Virtual Directory is displayed in Application Tier Summary under Public URL. It's the part of the URL that follows the server domain ("/VirtualDir" in the example below):
Open Team Foundation Server Administration Console from start menu and navigate to Application Tier. The Virtual Directory is listed in the Application Tier Summary:
