Getting local admins from all PCs

ianicepi 

check the following hope it helps to improve your script 

# Function to get local admins for a single computer
function Get-LocalAdmins {
    param(
        [string]$computerName
    )

    try {
        # Use Get-WmiObject to retrieve local administrators more reliably
        $admins = Get-WmiObject -Class Win32_GroupUser -ComputerName $computerName -Filter "GroupComponent='Win32_Group.Domain=\"$computerName\",Name=\"Administrators\"'"
        if ($admins) {
            foreach ($admin in $admins) {
                $account = Get-WmiObject -Class Win32_UserAccount -ComputerName $computerName -Filter "Name='$($admin.PartComponent -split ',')[1]'"
                [PSCustomObject]@{
                    Device = $computerName
                    User = $account.Name
                    IsAdmin = $true
                }
            }
        }
    }
    catch {
        Write-Warning "Failed to get local admins for $computerName: $_"
        # Optionally, send error details to your Flow
    }
}

# Get all computer names in your domain or desired scope
$computerNames = Get-ADComputer -Filter * | Select-Object -ExpandProperty Name

# Process each computer
foreach ($computerName in $computerNames) {
    $admins = Get-LocalAdmins -computerName $computerName
    if ($admins) {
        # Convert admin data to JSON and send to your Flow
        $body = ConvertTo-Json $admins
        Invoke-RestMethod -uri $URI -Method Post -body $body -ContentType 'application/json' 
    }
}