Hello Ignat Miller,
You need to install 32 bit Direct Show filter for a specific format. Please check a LAV decoder or a codec pack which contains a variety of codecs for different formats, e.g. K-lite codec pack. Anyway, please keep in mind, that you can not edit a raw opus file, while you can try to edit multiplexed file (e.g. mp4, mkv, webm or other file, that contains opus-encoded audio stream).