1. First, import the video material that needs matting in the clip and add it to the timeline. Click the video footage on the timeline, and select "chroma matting" from the menu on the right.

2. Secondly, in the "chroma matting" interface, use the "color picker" tool to select the color of the text to be cropped, and adjust the parameters of "intensity" and "shadow" to obtain the best matting effect.

3. Finally, click OK to finish the matting operation.