The Media Extensions feature built into macOS lets you use third-party media formats that aren’t natively supported in Final Cut Pro.
Note: The Media Extensions feature requires macOS Sequoia or later.
Download and install the media extension for the third-party media format you want to use.
In Final Cut Pro, choose Apple menu 
in the sidebar, then click Login Items & Extensions. (You may need to scroll down.)
In the Extensions section, click the Info button next to Media Extensions, turn on any format readers, decoders, or processors for the media extension (you may need to scroll down), then click Done.
Quit Final Cut Pro (if it’s open), then reopen Final Cut Pro.
You can now import and edit with video encoded in the third-party media format.
In Final Cut Pro, import a video clip that’s encoded in the third-party media format.
Select the third-party media clip in the browser or timeline.
Open the Info inspector.
Tip: Double-click the top bar of the inspector to switch between half-height view and full-height view.
Scroll down to the Media Extensions section of the Info inspector to view installed media extensions.
A green dot next to a media extension indicates that the media extension is being used to decode the selected video clip. If there’s an issue, a red triangle appears. Click the Extension Settings button to open System Settings and resolve the issue.
To view or adjust settings for third-party RAW media formats, click Edit RAW Properties.
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