function list_all_files_inside_one_folder_without_subfolders(){
  var sh = SpreadsheetApp.getActiveSheet();
  var folder = DriveApp.getFolderById('1mx-C16lEB22Y-ZHx1-BurfGWa6jKSnOi'); // change the folder ID  here 
  var list = [];
  sh.getRangeList(['A1:Z999']).clearContent()
  list.push(['Name','Type','Size','Url']);
  var files = folder.getFiles();
  while (files.hasNext()){
    file = files.next();
    var row = []
    row.push(file.getName(),file.getMimeType(),file.getSize(), file.getUrl())
    list.push(row);
  }
   sh.getRange(1,1,list.length,list[0].length).setValues(list);
}