This is a revised version of an AnyBox example.

ProcessManager.ps1

#requires -version 5.1
#requires -RunasAdministrator
#requires -module AnyBox

# https://www.fresh2.dev/doc/anybox/
# this is a revised version of the example at https://github.com/fresh2dev/AnyBox/blob/main/Examples/Process-Mgr.ps1

Param([string]$Computername = $env:Computername)
$anybox = New-Object AnyBox.AnyBox

$anybox.Title = 'Process Mgr'
$anybox.ResizeMode = 'CanResizeWithGrip'
$anybox.MaxHeight = 800
$anybox.MaxWidth = 600
$anybox.Topmost = $true
$anybox.AccentColor = 'Black'

$anybox.GridData = @(Get-CimInstance -Class Win32_Process -ea Stop | Select-Object ProcessId, ProcessName, CommandLine)
$anybox.NoGridSearch = $true
$anybox.SelectionMode = [AnyBox.DataGridSelectionMode]::MultiRow

# Define the computer name prompt; the field must not be empty and the computer must be online.
$paramHash = @{
    Group            = 0
    Name             = 'pcName'
    Message          = 'Computer Name:'
    MessagePosition  = 'Left'
    DefaultValue     = $Computername.ToUpper()
    ValidateNotEmpty = $True
    ValidateScript   = { Test-Connection $_ -Count 1 -Quiet -ErrorAction SilentlyContinue }
}
$anybox.Prompts = @(New-AnyBoxPrompt @paramHash)

# Define the process filter prompt
$paramHash.Name = 'pFilter'
$paramhash.Message = '    Process Name:'
$paramHash.DefaultValue = "*"
$paramHash.Remove('ValidateScript')
$anybox.Prompts += @(New-AnyBoxPrompt @paramhash)

# Define the 'Refresh' button.
$anybox.Buttons = New-AnyBoxButton -Text 'Refresh' -IsDefault -OnClick {
    # Run 'Test-ValidateInput' to enforce
    # the validation parameters set on the 'pcName' prompt.
    $input_test = Test-ValidInput -Prompts $Prompts -Inputs $form.Result
    if (-not $input_test.Is_Valid) {
        $null = Show-AnyBox @childWinParams -Message $input_test.Message -Buttons $(New-AnyBoxButton -Text 'OK' -IsDefault)
        $form['data_grid'].ItemsSource = $null
    }
    else {
        [string]$msg = $null
        try {
            # Get all running process matching the filter.
            # '$_.pcName' will access the text in the 'pcName' prompt.
            # '$_.pFilter' will access the text in the 'pFilter' prompt.
            $new_data = @(Get-CimInstance -ComputerName $_.pcName -Class 'Win32_Process' `
                    -Filter "Name LIKE '$($_.pFilter.Replace('*', '%'))'" -ea Stop |
                    Select-Object ProcessId, ProcessName, CommandLine)

            if ($new_data.Length -eq 0) {
                $form['data_grid'].ItemsSource = $null
                $msg = 'No processes match the provided filter.'
            }
            else {
                # Update the grid with matching processes.
                $form['data_grid'].ItemsSource = $new_data
            }
        }
        catch {
            $msg = $_.Exception.Message
        }

        # If an error occurs, show another AnyBox.
        # Show a child window with @childWinParams.
        if ($msg) {
            Show-AnyBox @childWinParams -Message $msg -Buttons 'OK'
        }
    }
}

$anybox.Buttons += New-AnyBoxButton -Text  "Export to CSV" -onclick {

    $savePrompt = Show-AnyBox @childwinparams -MinWidth 350 -Buttons 'Cancel', 'Export' -Prompt @((New-AnyBoxPrompt -InputType 'FileSave' -Message 'Specify the filename and path for the CSV file.' -ReadOnly))

    if ($savePrompt.Export) {
        $form['data_grid'].ItemsSource |
        Add-member -MemberType NoteProperty -name Computername -value $_.pcname.toUpper() -passthru |
        Export-CSV -path $savePrompt.Input_0
        Show-Anybox @childWinParams -title 'CSV Export' -Messages "Data saved to $($savePrompt.Input_0)" -buttons "OK" -MinWidth 250
    }
    }
$anybox.Buttons += New-AnyBoxButton -Text 'Kill' -OnClick {
    # Run 'Test-ValidateInput' to enforce
    # the validation parameters set on the 'pcName' prompt.
    $input_test = Test-ValidInput -Prompts $Prompts -Inputs $form.Result
    if (-not $input_test.Is_Valid) {
        $null = Show-AnyBox @childWinParams -Message $input_test.Message -Buttons $(New-AnyBoxButton -Text 'OK' -IsDefault)
        $form['data_grid'].ItemsSource = $null
    }
    else {
        # Access selected grid rows with 'grid_select'.
        [array]$toKill = @($_.grid_select | Select-Object ProcessId, ProcessName)

        if ($toKill.Length -eq 0) {
            $null = Show-AnyBox @childWinParams -Message 'Select processes to kill.' -Buttons 'OK'
        }
        else {
            # Confirm before killing the selected processes.
            $answer = Show-AnyBox @childWinParams -Message 'Are you sure you want to kill the following processes?' `
                -GridData $toKill -Buttons 'Cancel', 'Confirm'

            if ($answer['Confirm']) {
                [string]$pcName = $_.pcName

                $killed = @($toKill | ForEach-Object {
                        [int]$code = 0
                        [string]$msg = $null

                        try {
                            $code = Get-CimInstance -ClassName win32_process -Filter "processid= $($_.processid)" -ComputerName $PCName |
                                Invoke-CimMethod -Name Terminate | Select-Object -ExpandProperty ReturnValue
                                #([wmi]"\\$pcName\root\cimv2:Win32_Process.Handle='$($_.ProcessId)'").Terminate().ReturnValue
                                if ($code -eq 0) {
                                    $msg = 'Successfully closed.'
                                }
                            }
                            catch {
                                $code = -1
                                $msg = $_.Exception.Message
                            }

                            $_ | Select-Object ProcessId, ProcessName, @{Name = 'Code'; Expression = { $code } }, @{Name = 'Message'; Expression = { $msg } }
                        })

                    [string]$msg = $null
                    try {
                        $new_data = @(Get-CimInstance -ComputerName $_.pcName -Class 'Win32_Process' `
                                -Filter "Name LIKE '$($_.pFilter.Replace('*', '%'))'" -ea Stop |
                                Select-Object ProcessId, ProcessName, CommandLine)

                    if ($new_data.Length -eq 0) {
                        $form['data_grid'].ItemsSource = $null
                    }
                    else {
                        $form['data_grid'].ItemsSource = $new_data
                    }
                }
                catch {
                    $msg = $_.Exception.Message
                }

                # Output the results in child AnyBox with a DataGrid.
                $null = Show-AnyBox @childWinParams -GridData $killed -Buttons 'OK'

                # If an error occurred, show it in a child AnyBox.
                if ($msg) {
                    $null = Show-AnyBox @childWinParams -Message $msg -Buttons 'OK'
                }
            }
        }
    }
}

$anybox.Buttons += New-AnyBoxButton  -Text Quit -IsCancel

[void]($anybox | Show-AnyBox)

Some screen shots: