Issues in trimming a video with FFmpeg

I have a .webm video captured through a web browser. Using ffmpeg, I want to trim it into its first 30s without re-encoding and quality degradation. But I have issues doing it and ffmpeg complains about it.

What is the problem? How can I address it?

ffmpeg -i video.webm -to 30 -c copy out.webm


[webm @ 0000014ea3249a00] Only VP8 or VP9 or AV1 video and Vorbis or Opus audio and WebVTT subtitles are supported for WebM.
Could not write header for output file #0 (incorrect codec parameters ?): Invalid argument
Error initializing output stream 0:1 --

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