How do I remove the background from a video using Apple Shortcuts integration with Pixelmator Pro?

I have a video file (MP4 file format, 4K resolution, 5 seconds long) and I'm trying to figure out a workflow that would allow me to cut out/separate the actor in the video by creating a Luma Matte for each video frame. I've been experimenting with Apple Shortcuts integration with Pixelmator Pro on my Mac to solve this.

Essentially, what the Shortcut would need to be able to do:

1 - Import the video file.

2 - Convert every video frame to an image frame.

3 - Create a Luma Matte for the actor in each image frame.

4 - Save out all of the Luma Matte frames as image files (OR even better: put together all of the Luma Matte image files into a new video file).

I've been experimenting without succeeding with the setup in the screenshot below (note that some parts of it is in Swedish due to my macOS being set to Swedish). I believe I might need some solution where it repeats the action for each frame or something? Is there any Apple Shortcuts guru here who can show me how to set up this properly?

(And no: I don't want to use any video rotoscoping tools or similar, I want this solution since the Pixelmator Pro image background removal AI is fantastic for keying out hair, which is why I want to see if it is possible to use it in this way).