$ClientId = ""
$SiteUrl = "https://tenantName.sharepoint.com/sites/siteName"
Connect-PnPOnline -Url $SiteUrl -Interactive -ClientId $ClientId

$list = Get-PnPList -Identity "listName"

Write-Output "List Template Name: $($list.TemplateTypeDisplayName)"

Write-Output "List Template ID: $($list.BaseTemplate)"