If documents are deleted from first-stage recycle bin, those documents can be restored from second-stage recycle bin.
There is second-stage recycle bin in SharePoint which is accessible to site collection administrators.
A SharePoint site collection administrator can view and restore deleted items from the site collection Recycle Bin to their original ...
You could try the code in the blog:
#PowerShell Function to copy permissions between Folders in SharePoint Online
[Parameter(Mandatory=$True)] [string] $WebURL,
[Parameter(Mandatory=$True)] [string] $SourceFolderURL,