Unknown key_frame and pict_type of encoded H.266 video stream

I converted a sample video from H.264 into H.266 using FFmpeg (with the VVenC support) with such a command:

ffmpeg -i input.mp4 -c:v libvvenc -b:v 2600k -preset faster output.mp4

Then I checked the content of the encoded frames with such a command:

ffprobe output.mp4 -show_frames

It occurs that for all of the frames key_frame=0 and pict_type=?, so it looks like FFmpeg does not know anything about intra frames of H.266 video stream.

So my question is:

• is it supported to distinguish between I-frames and P/B-frames when using H.266 codec?

I expected at least one intra frame at the beginning of the video, but it looks like there are no such frames types.