FCPX only supports FCPXML Captions or FCPXML Titles on an FCP Project itself.
You cannot caption or title an audio/video clip. If you import a clip either via the extension or the website, you will *not* receive FCPXML Captions/Titles. (Instead you will then need to export SRT subtitles and import that to FCPX.)
This means to receive Captions or Titles, you need to:
1. Have the Simon Says Extension installed into FCPX (See here for instructions to install)
2. Have an FCP Event with an FCP Project.
If your FCP Project contains just simple clips, skip to step 3 where you import the FCP Event (with the FCP Project) to the Simon Says Extension.
If you have MC, sync or compound clips in the FCP project/sequence, then please create a "clean" FCP Project so only the pertinent parts of the utilized clips import. (We will soon be adding support for complex clips in FCP projects/sequences.)
Here is how to get a clean FCP project:
a. Take your final edit FCP project and export it without sound effects/music to a clip. (This is so the dialogue track is clear and thus the AI accuracy will be higher.)
b. Import that clip back to FCP and place it into a new, clean FCP project in an FCP Event.
Yes, this is an extra step versus just importing a final edit FCP Project but it will lead to the most cost-effective and most accurate result.
3. Drag that Event with the clean FCP Project to the Simon Says Extension
5. Then export and drag the FCP Captions or FCP Titles icons back to your FCP Event
TaDa! You will now have FCP Captions / Titles.
FYI: The benefit of using Titles is it provides much more opportunity to adjust font size/styles than Captions.
Related Help Articles:
Best Practices for importing Multicam and Sync clips with the SS FCP X Extension
Optimizing your FCP X Ranges XML
Export burnt-in subtitles/caption in FCPX
How-to: getting started with the FCP X Extension (video)