Bulk check-in files in SharePoint online large list

Question

trying to bulk check in files in a list containing over 400K files tried without CAML query, but it takes forever. with the query, getting threshold error even with rowlimit. is there any other way?

$Result = @() #Result array
  
#Provide SPO Site URL   
$SiteUrl = "https://contoso"
  
#Provide List/Document Library name 
$ListName = "list"
  
#Connect to PnP Online
Connect-PnPOnline -Url $SiteURL -interactive
  
#CAML Query to filter only Checked-out files
$CAMLQuery = "
<View Scope='RecursiveAll'>
    <Query>
        <Where>
            <IsNotNull><FieldRef Name='CheckoutUser' /></IsNotNull>
        </Where>
    </Query>
    <RowLimit>1000</RowLimit>
</View>"
   
#Query All Checked out files
$ListItems = Get-PnPListItem -List $ListName -PageSize 1000 -Query $CAMLQuery   
$i = 0;
$TotalFiles = $ListItems.Count
 
#Iterate checked-out files one by one and check-in
.......