just call the function by passing the URL parameter for the mp3 file and wait for the promise to finish.

await id3(url);
// or
id3(url).then(callback);

some examples include:

let data = await id3(blob);
data["TIT2"] // song title
data["TPE1"] // artist
data["TYER"] // year
// and if available...
data.image // image data stored as Uint8Array
data.image_mime // mime type of the image

the available tag names and values are fully presented here: https://exiftool.org/TagNames/ID3.html