Upload the video, choose Dub, tick "Use my subtitle file as the script" and add your .srt or .vtt. Your lines are read aloud at their timestamps over the video, translated first if the file is in another language, and you get a dubbed MP4 and MP3.
1 credit a minute to transcribe the video (for its length and sound), plus 2 to dub, plus 1 to translate your file if it is in another language. Dubbing and translation are charged when the dub is delivered.
They are your reviewed wording: names, terms and phrasing stay as you wrote them.