Review automatic captions and edit or remove any parts that haven't been properly transcribed.Under Subtitles, click More next to the subtitles that you want to edit.Click the video that you want to add captions or subtitles to.From the left-hand menu, select Subtitles.Here's how you can review automatic captions and make changes, if needed:

Always review automatic captions and edit any parts that haven't been properly transcribed. However, automatic captions might misrepresent the spoken content due to mispronunciations, accents, dialects or background noise. YouTube is constantly improving its speech recognition technology. Processing time depends on the complexity of the video's audio. Automatic captions may not be ready at the time that you upload a video. If automatic captions are available, they'll be published automatically on the video. We encourage creators to add professional captions first. If there are multiple language audio tracks on a video, the automatic captions will be in the default language. Automatic captions are available in Arabic, Dutch, English, French, German, Hindi, Indonesian, Italian, Japanese, Korean, Polish, Portuguese, Romanian, Russian, Spanish, Thai, Turkish, Ukrainian and Vietnamese.

Youtube auto caption