This is the loading screen while captions are generating - the progress indicator will update automatically. As indicated, captions can take up to 2x the length of your video, but will likely be faster than that.
For example, if your video is 5 minutes long it could take up to 10 minutes to generate captions. You do not need to stay on this page for the generation to complete! You can keep the captions generation page open and continue working on other things in a different tab or window. Once captions are done generating, this page will automatically change to the 'Edit Captions' page.