ffmpeg to concat list of videos without txt

Question

iven been trying different ways to concat the list of videos called videoPaths but it doesnt work so i tried this way but it results in a zero byte file

  mergeVideos() async {
    String commandToExecute = '-y -i ${videoPaths[0]} -i 
    ${videoPaths[1]} -r 24000/1001 -filter_complex \'[0:v:0] 
    [0:a:0][1:v:0][1:a:0]concat=n=2:v=1:a=1[out]\' -map \'[out]\' 
    $outputPath';
    print(commandToExecute);
    FFmpegKit.execute(commandToExecute).then((session) async {
      print(await session.getOutput());
    });
  }

Ive also tried this but fails with return code 1

Future<void> concatenateVideos() async {
    try {
      String command = '-i ${videoPaths.join(' -i ')} -filter_complex concat=n=${videoPaths.length}:v=1:a=1 -y $outputPath';

      FFmpegSession session = await FFmpegKit.executeAsync(command);

      ReturnCode? returnCode = await session.getReturnCode();

      if (returnCode == ReturnCode.success) {
        print('Concatenation completed successfully!');
      } else {
        print('Error during concatenation. FFmpeg return code: $returnCode');
      }
    } catch (e) {
      print('Error: $e');
    }
  }