Add-Type -Path "C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\16\ISAPI\Microsoft.SharePoint.Client.dll"
Add-Type -Path "C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\16\ISAPI\Microsoft.SharePoint.Client.Runtime.dll"

$xmlFilePath = "C:\Users\elonguir\Documents\Script-SiteColumns.xml"

$SiteCollURL = ""
$UserName = ""
$Password = ""
$SecurePassword= ConvertTo-SecureString $Password –asplaintext –force

#Bind to site collection
$Context = New-Object Microsoft.SharePoint.Client.ClientContext($SiteCollURL)
$Creds = New-Object Microsoft.SharePoint.Client.SharePointOnlineCredentials($UserName,$SecurePassword)
$Context.Credentials = $Creds
$Web = $Context.Web

#Create Export Files
New-Item $xmlFilePath -type file -force

#Export Site Columns to XML file
Add-Content $xmlFilePath "<?xml version=`"1.0`" encoding=`"utf-8`"?>"
Add-Content $xmlFilePath "`n<Fields>"
$Context.Load($Web.Fields)
$Context.ExecuteQuery()
$Web.Fields | ForEach-Object {
    $Context.Load($_)
    $Context.ExecuteQuery()
    if ($_.Group -eq "Enterprise Keywords Group") {
        $Context.Load($_)
        $Context.ExecuteQuery()
        Add-Content $xmlFilePath $_.SchemaXml
    }
}
Add-Content $xmlFilePath "</Fields>"