OpenAI Whisper API: Unable to convert URI to a compatible file type

Question

I'm basically calling OpenAI's audio transcription API to convert an audio file to text. I understand that the API requires a file type of Core.Uploadable, thus appending current timestamp lastModified to the file creation.

An URI example is: file:///var/mobile/Containers/Data/Application/D19779A9-081C-4A53-B872-1492416A3ACD/Library/Caches/ExponentExperienceData/@anonymous/my-ai-assistant-84e367f8-fea0-4610-b263-9dfbe9752bc8/AV/recording-421304D5-BAF4-4CFF-9991-3838D1EE3398.m4a

I'm not sure why the model is not accepting the file.

export async function getTranscription(uri: string): Promise<string> {
  try {
    // Fetch the file from the given URI
    const response = await fetch(uri);
    if (!response.ok) {
      throw new Error(`Failed to fetch file: ${response.statusText}`);
    }

    // Convert the response to a Blob
    const blob = await response.blob();

    // Create a File from the Blob
    const file = new File([blob], "audio.m4a", {
      type: "audio/m4a",
      lastModified: Date.now(),
    });

    // Send the File to Whisper transcription API
    const transcription = await openai.audio.transcriptions.create({
      file: file,
      model: "whisper-1",
      language: "en",
    });

    console.log(transcription.text);
    return transcription.text;
  } catch (error) {
    console.error("Error during transcription:", error);
    throw error;
  }
}

I get:

(NOBRIDGE) ERROR  Error during transcription: [Error: 400 [{'type': 'missing', 'loc': ('body', 'file'), 'msg': 'Field required', 'input': None}]]   
(NOBRIDGE) ERROR  Failed getting transcription [Error: 400 [{'type': 'missing', 'loc': ('body', 'file'), 'msg': 'Field required', 'input': None}]]