You can edit and re-upload the video, but that means losing all your comments and engagement metrics. You can add a note to the video’s description or pin a comment with the correction.
After a video has been uploaded, creators can add corrections that will appear as InfoCards in the top right-hand corner of a video. Viewers can then click on the card to expand the correction notes in the video’s description notes.
Youtube’s creator insider channel lets you see a video description of the new feature. You can see the full instructions for how to add corrections.