Once you are completely happy with your translation and the timings of your captions, click ‘Approve’ and a producer will be notified automatically that you are finished.
Please note that you will be unable to approve captions if CaptionHub detects that they're in breach of the limits. For more information about limits, see this article.
If you spot something at the last minute having already approved your work, contact the project producer. They will be able to unapprove it, and return control of the caption set to you.