Sql-server – Invoke-Sqlcmd : A network-related or instance-specific error occurred while establishing a connection to SQL Server

I want to create a table using .sql file through PowerShell.

Running following in Windows PowerShell ISE as Administrator:

Invoke-Sqlcmd -InputFile 'D:\SQL Scripts\test.sql' -ServerInstance 'localhost\MSSQLSERVER' -Database 'Test'

But this is giving following error:

Invoke-Sqlcmd : A network-related or instance-specific error occurred while establishing a connection to SQL Server. The
server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to
allow remote connections. (provider: SQL Network Interfaces, error: 25 – Connection string is not valid)

Could any one please guide to fix this.

I have already refereed execute .sql using powershell