To import using powershell, it will works only with CSV file.
you need to first import CSV file and then in ForEach loop needs to create items in sharepoint
$ImportSharedCSV=Import-Csv P:\temp\1.csv
$ImportSharedCSV.Values
foreach ($line in $ImportSharedCSV)
{
$fieldvalue=$line.values
$MaterialCode= $fieldvalue.Split("~")[0];
// you can sets your varialbe name as field name above array columns
$item=@{
"Title"=$MaterialCode
}
Add-PnPListItem -List listname -Values $item -ContentType Item -ErrorAction Stop
}