List all site collection owners with PnP-PowerShell

gistfile1.txt

$tenant = "<PutYourTenantIdHere>"
$env:ClientId = "<PUTYourAppIdHere>"
$env:ClientSecret = "<PUTYourAppSecretHere>"
$fileExportPath = "<PUTYOURPATHHERE.csv>"

Connect-PnPOnline https://$tenant-admin.sharepoint.com -ClientId $env:ClientId -ClientSecret $env:ClientSecret

$results = @()
$sites = Get-PnPTenantSite
$sites | ForEach-Object {
    $site = $_
    Write-Host "Processing $($site.Url)"
    Connect-PnPOnline $site.Url -ClientId $env:ClientId -ClientSecret $env:ClientSecret
    $owners = Get-PnPSiteCollectionAdmin
    foreach($owner in $owners){
        $results += [pscustomobject][ordered]@{
            SiteUrl = $site.Url
            LoginName = $owner.LoginName
            Title = $owner.Title
            Email = $owner.Email
        }
    }
}
Write-Host "Exporting file to $fileExportPath..."
$results | Export-Csv -Path $fileExportPath -NoTypeInformation
Write-Host "Completed."