youtube video download error

1. Check if the proxy address is filled in correctly. The correct proxy address is in the format http://127.0.0.1:portnumber. Do not enter random content.
2. Downloading a YouTube video involves downloading the video and audio as two separate files, which are then merged into an mp4 file. If you open the video file during the download process, it will definitely have no sound. Please wait patiently for the download to complete and the merging to finish.