Foreach ($File in (dir $LocalBckupFolder))
{
    $StartAFile = get-date -uformat "%Y-%m-%d %H:%M:%S"
    Add-Content $log "$StartAFile :: Start Upload file: $File.name"
    $FileStream = New-Object IO.FileStream($File.FullName,[System.IO.FileMode]::Open)
    $FileCreationInfo = New-Object Microsoft.SharePoint.Client.FileCreationInformation
    $FileCreationInfo.Overwrite = $true
    $FileCreationInfo.ContentStream = $FileStream
    $FileCreationInfo.URL = $File
    $Upload = $SPfolder.Files.Add($FileCreationInfo)
    $ctx.Load($Upload)
    $ctx.ExecuteQuery()
    $FinishAFile = get-date -uformat "%Y-%m-%d %H:%M:%S"
    Add-Content $log "$FinishAFile :: Done Upload file: $File.name"
}

$ctx.Dispose()

$username = "admin@domain.onmicrosoft.com"
$password = "Password"
$url = "https://domain.sharepoint.com/sites/Test"
$path = "C:temptest";
$destination = $url + "/Shared Documents"; #lib partial url

$securePassword = ConvertTo-SecureString $Password -AsPlainText -Force

# the path here may need to change if you used e.g. C:Lib..
Add-Type -Path "c:Program FilesCommon Filesmicrosoft sharedWeb Server Extensions15ISAPIMicrosoft.SharePoint.Client.dll"
Add-Type -Path "c:Program FilesCommon Filesmicrosoft sharedWeb Server Extensions15ISAPIMicrosoft.SharePoint.Client.Runtime.dll"

# connect/authenticate to SharePoint Online and get ClientContext object..
$credentials = New-Object Microsoft.SharePoint.Client.SharePointOnlineCredentials($username, $securePassword)

$webclient = New-Object System.Net.WebClient;
$webclient.Headers["Cookie"] = $credentials.GetAuthenticationCookie($url)

Get-ChildItem $path | Where-Object {$_.Length -gt 0} | ForEach-Object {
    $webclient.UploadFile($destination + "/" + $_.Name, "PUT", $_.FullName);
};