Capture. open (path) in Linux environment, Videoio.CAP_FFMPEG); An error occurred

[CK-henry]

I encountered an error when loading an MP4 video using capture.open, as if the ffmpeg module was not loaded.
The environment is Unity 2021.3.39, OpencvforUnity version 2.6.1. Below are some loading logs
Video I/O:
DC1394: NO
GStreamer: NO
v4l/v4l2: YES (linux/videodev2.h)

Parallel framework: pthreads