THE SHORT ANSWER
Here's the approach.
Export File creates a high-quality output that you can deliver or use in another post-production step. Select the project for a complete export. To export only part of a timeline, set a range; selecting an individual timeline clip is not enough.
If you edited with proxies, choose Optimized/Original in the viewer before exporting. Review the destination settings because changing them also changes that destination’s defaults.
Related tutorial.
Starts at 53:05, Sharing a MovieThis is a supplemental tutorial. Its compatibility with Final Cut Pro 10.8 has not been confirmed. Use the written steps and version-specific sources for the controls.
By Ripple Training. YouTube oEmbed confirmed the title, creator and thumbnail. The software version shown in this video has not been verified. No watched-content review, answer timestamps, transcript, duration or upload date is asserted. Playback was not tested.
Step by step.
Final Cut Pro 10.8- 01
Choose the project or range
Select the project in the browser, or set the required timeline range with I and O.
- 02
Return to full-quality media
Open the project in the timeline and choose Optimized/Original from the viewer View menu.
- 03
Open Export File
Choose File > Share > Export File. Review the information pane, then use Settings to choose the required format and codec.
- 04
Save the output
Click Next, choose a location, and click Save. Follow progress in Background Tasks, then inspect the resulting file.
Sources & version notes
Written for Final Cut Pro 10.8. Menu names and available features can differ in other versions.
Version reference: Final Cut Pro 10.8Written answer checked against the linked official documentation for Final Cut Pro 10.8. Related videos have metadata verification only; they are supplemental resources, with no verified answer-specific timestamps or software-version compatibility assertion.