I have a task to create two Business Central Server and Webserver Instances.
I have successfully created two Server Instances that are BC240 and BC240_Test.
New-NAVWebServerInstance -WebServerInstance BC240_Test -Server localhost -ServerInstance BC240_Test -ClientServicesCredentialType Windows -ClientServicesPort 24146
NOTE I have tried executing the command on BC24 admin shell and as well as Importing NAVAdminTool.ps1 on PowerShell ISE.