A YouTube QR code links to a video, Short, playlist, or channel that is already on YouTube, so there is nothing to upload and nothing to host. When someone scans it with their phone's camera, the link opens in the YouTube app or on youtube.com in the browser, depending on the phone. On the free plan, a short QR Cake page shows first. The video is watched on YouTube itself, so views count toward your channel under YouTube's normal rules, and viewers land on the video's own page with your subscribe button, likes, comments, and recommended videos in place.
If you can copy a YouTube link, you can make the code. A youtube.com watch URL, a youtu.be short link from the Share button, a Shorts link, a playlist URL, or your channel's @handle URL all work the same way. A link with a start time (the Start at box in YouTube's desktop Share window) opens the video at the moment that matters. There is no file size limit and no hosting bill, because YouTube does the streaming.
Once you save the code to your QR Cake account, it is dynamic: the printed pattern holds a short QR Cake link rather than the YouTube URL. When you publish a better cut or a new season's clip, open the code in your dashboard and paste the new YouTube link. Every copy already printed on packaging, posters, business cards, or handouts opens the new video, with no reprint. A static QR code encodes the YouTube URL into the pattern itself, so changing the video means reprinting everything.