add-type -Path "C:admintoolsspOnlineDLLsMicrosoft.SharePoint.Client.dll"
add-type -Path "C:admintoolsspOnlineDLLsMicrosoft.SharePoint.Client.Runtime.dll"
$SiteUrl = "https://companyname.sharepoint.com/sites/mySPSite"
$ListName = "testList"
$UserName = "my.email@companyname.com"
$SecurePassword = convertto-securestring -string "P@ssw0rd" -AsPlainText -force

$ClientContext = New-Object Microsoft.SharePoint.Client.ClientContext($SiteUrl)
$credentials = New-Object Microsoft.SharePoint.Client.SharePointOnlineCredentials($UserName, $SecurePassword)
$ClientContext.Credentials = $credentials

# Get List and List Items
$List = $ClientContext.Web.Lists.GetByTitle($ListName)
$ListItems = $List.GetItems([Microsoft.SharePoint.Client.CamlQuery]::CreateAllItemsQuery())
$ClientContext.Load($List)
$ClientContext.Load($ListItems)
$ClientContext.ExecuteQuery()

[System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SharePoint.Client")
 [System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SharePoint.Client.Runtime")