I install SQLServer module and tried again but getting the same error: See below:

PS SQLSERVER:\> Get-Module SqlServer -ListAvailable

  Directory: C:\Program Files\WindowsPowerShell\Modules

ModuleType Version  Name           ExportedCommands
---------- -------  ----           ----------------
Script  21.0.17224 SqlServer

Do i need to reboot my machine after installing the module?