Vue js command trouble

Hello guys.
I'm using your library for my new Vue js project, it`s very helpfull, thank's for that!
Also I have a trouble with such command:
RAW ffmpeg command look like this:

ffmpeg -i inputVideo.flv -vf select=eq(pict_type\\,I),scale=400x320 -vsync vfr -qscale:v 2 thumbnails-%02d.jpeg

My portation using your library looks like this:

await ffmpeg.run(
'-i',
'inputVideo.flv',
'-vf',
'select=eq(pict_type\\,I),scale=400x320',
'-vsync',
'vfr',
'-qscale:v',
'2',
'thumbnails-%02d.jpeg',
);

I always took an error like "select command not found" or another like this one.
Maybe I using this not in right way, but also I dont find any kind of documentation for using Select command.(
I would be extremely grateful for your help.
Thank's in advance, Nikolay.