[h264_nvenc] How to enable decode on GPU?

[steam3d]

I use ffmpeg and i can decode video on GPU using h264_nvenc

cmd = '{0}  -i "{1}" -vcodec h264_nvenc  -acodec aac  "{2}"'
# {0} - ffmpeg path
# {1} - input file
# {2} - output file

How can i use h264_nvenc in post-processing options?

[kfur]

Try --postprocessor-args

[steam3d]

I tried this and got error

youtube_dl.utils.DownloadError: ERROR: h264_nvenc: Invalid argument

options = {
    'mp4': {'nocheckcertificate': True,
            'outtmpl': dlpath,
            'ffmpeg_location': ffmpegpath,
            'forcefilename': True,
            'format': 'bestvideo/best',
            'postprocessors': [{
            'key': 'FFmpegVideoConvertor',
            'preferedformat':'mp4'
			}],
            'logger': MyLogger(signal),
            'progress_hooks': [my_hook],
            'postprocessor_args': ['h264_nvenc'],
            },
}

Update. I replaced 'postprocessor_args': ['h264_nvenc'] to 'postprocessor_args': ['-c:v h264_nvenc'], and got this error

youtube_dl.utils.DownloadError:` ERROR: At least one output file must be specified

But i choose the output file 'outtmpl': dlpath,