To Bulk Automatic Caption items in your Media Library, select the content from the Media Library by clicking the corresponding checkbox for each desired item, then click Bulk Automatic Caption.
A new window will ask you to confirm the content selected. If any of the items on the list are not meant to be included in the Bulk Automatic Captioning operation, press the x icon next to that item to exclude it. Click Caption if the list is correct. Click Close to cancel the Bulk Automatic Captioning operation and return to the Media Library.
Note: Selected items that can not be captioned, that have already been captioned, or that are pending captioning, have been excluded.
The Caption button will generate captions for the selected files, which will be usable in the video player as soon as the captions are completed.
For a full description of automatic captioning, see the Automatic Captioning guide.