[react.js] Modify JavaScript screen recording sample(avi or mp4)

I looked for open source samples that do screen recording in react.js.
https://github.com/ICODER32/ScreenRecorder.git
https://github.com/jamumar/Screen_Recorder.git

However, the samples above seem to forcibly change the file name to mp4 after recording the file in 'video/webm' type.


(example)
1. Create video with webm type
new Blob(recordedChunks, { type: 'video/webm' });

2. Force webm file rename
a.download = 'recorded-video.mp4';
=========================================


[Problems with the sample above]
If a webm type file is forcibly renamed to mp4, the video is damaged and does not operate normally. (The time of the video being watched could not be changed forward or backward.)

For example, if I recorded a video that was 45 minutes in total, I couldn't go back to 13 minutes after watching it until 28 minutes.
And if I recorded a total of 58 seconds of video, I couldn't watch it until 4 seconds and immediately jump to 47 seconds.

So I found a video file download sample that works normally with common video types such as avi or mp4 (h264).


[Requirements]
1. Please provide me with a sample project to download video files in common video types such as avi or mp4 (h264), not webm.

2. After uploading the result to GitHub without the node_modules folder, let us know the url.
Then, after downloading the project, I will execute 'yarn(npm install)' → 'yarn start' command and check the result.