Not Saving?

[everythingability]

Hi,

I'm getting an error when trying to save in Tamotsu... this is my code

function loopThroughItemsWithTamotsu() {
  Tamotsu.initialize();
  var agent = Tamotsu.Table.define({ sheetName: 'Redirects', idColumn: 'Slug', });
  var rows = agent.order('Slug').all() // or .where(), find(), order(), first, last(), .pluck() or function 

  for (i = 0; i < rows.length; i++) {

    var url = rows[i]['Image']
    var thumbnailURL = GDriveURLToThumbnail(url)
    Logger.log(thumbnailURL)
    rows[i]['Thumbnail2'] = thumbnailURL

  }

  rows.save()
}

and I get

rows.save is not a function

Can anyone see anything obviously wrong? Thanks...