child process spawn output file and directory in NodeJs

I am using ffmpeg with child process to merge audio and video, but when i am trying to download the file, it is downloading in the same folder, but i want it to download it in the public folder.

following is my code for the child process spawn.

// Start the ffmpeg child process
const ffmpegProcess = cp.spawn(ffmpeg, [
    // Remove ffmpeg's console spamming
    '-loglevel', '8', '-hide_banner',
    // Redirect/Enable progress messages
    '-progress', 'pipe:3',
    // Set inputs
    '-i', 'pipe:4',
    '-i', 'pipe:5',
    // Map audio & video from streams
    '-map', '0:a',
    '-map', '1:v',
    // Keep encoding
    '-c:v', 'copy',
    // Define output file
    'title.mp4',
], {
    windowsHide: true,
    stdio: [
        /* Standard: stdin, stdout, stderr */
        'inherit', 'inherit', 'inherit',
        /* Custom: pipe:3, pipe:4, pipe:5 */
        'pipe', 'pipe', 'pipe',
    ],
});

You can set the cwd option. It will set the path your child process execute its code. For instance if you liked to run your process at the root of your fs, you would do that:

............
], {
    cwd: '/',
    windowsHide: true,
    stdio: [
        /* Standard: stdin, stdout, stderr */
        'inherit', 'inherit', 'inherit',
        /* Custom: pipe:3, pipe:4, pipe:5 */
        'pipe', 'pipe', 'pipe',
    ],
});

so set the path to your public folder and then it should be download there.