I'm using a mac now. The YouTube converter on my mac is Cisdem Video Converter for Mac.
You can find the video on YouTube, add its URL to this app, then start the download.
Try this one converter https://benstoolset.com/video-converter
Why download YouTube videos at all? There may be various reasons for this. After downloading interesting videos to your smartphone, you can use them for entertainment on the train, plane, and wherever there is no good Internet. By downloading content via wi-fi at home, you save on mobile traffic. Downloading videos from YouTube to MP4 is surprisingly easy - and you can do it for free! This service provides convenient tools for downloading videos (both to a computer and to a mobile device).