HLS link extraction using youtube-dl-exec instead of youtube-dl

Question

I have an old system (nodejs) that extracts the HLS link from a youtube livestream. Its code looks something like:

ydl = require('youtube-dl');
ydl.exec(stream.url, ['--format=96', '-g'], {}, (err, output) => {
      if (err) throw err

      console.log('\nyoutube-dl finished HLS link extraction:');
      console.log(output.join('\n'));
      console.log('\n');
      hls_link = output[0];
      stream.vCap = new cv.VideoCapture(hls_link);//0);
      stream.vCap.set(cv.CAP_PROP_FRAME_WIDTH, width);
      stream.vCap.set(cv.CAP_PROP_FRAME_HEIGHT, height);
    });
}

I need to switch to the package youtube-dl-exec since youtube-dl's node wrapper is no longer supported and is out of date w.r.t. YouTube's formatting for my use case.

I've tried rewriting the above to something like the following:

ydl = require('youtube-dl-exec');
ydl(url, {format: 96, getUrl: true}).then((result) => {
    console.log(`got hls result: ${result}`);
}).catch((fail) => {
    console.log(`hls failure`};
});

However, I get that the failure case is always reached even though when I run the following in the terminal I get reasonable output:

yt-dlp -f 96 -g <url>

Am I converting the flags properly or is perhaps something else wrong with my approach?

Thanks!