Stoney's dumb GAS project 2

function shortenUrl() { 
  var ss = SpreadsheetApp.getActiveSpreadsheet();
  var sheet = ss.getSheets()[0];
  var longUrls = sheet.getRange("J3:J10").getValues();
  var writeValues = []
  
  for (var i =1 ; i <= numRows; i++) {
    var row = []
    var numRows = longUrls.getNumRows();
    var numCols = longUrls.getNumColumns();
    for (var j = 1; j <= numCols; j++) {
       var url = UrlShortener.Url.insert({
      longUrl: longUrls});
      var shortUrl = url.id;
      row.push(shortUrl)
    }
    writeValues.push(row)
  }
  
  sheet.getRange("M3:M10").setValues(writeValues);
  
}