converting midi to xml fails

[ultraGentle]

I'm getting FileError: WebMscore: FILE_UNKNOWN_TYPE when attempting to ingest a .mid file and output a .musicxml.

Here's my code to reproduce:

let file = fs.readFileSync(filePath, null); // note : besides null, which yields a buffer, I've tried 'binary' and 'utf-8'

function generateAudioViaWebMScore(file) {
    WebMscore.ready.then(async () => {
        const score = await WebMscore.load('mid', file, [], true);
        fs.writeFileSync(`converted.musicxml`, await score.saveXml());
        score.destroy();
    });
}

Is this by design/my error/a bug?

Thanks for any suggestions!

[ultraGentle]

solved: webMscore wants midi not mid in the .load method