Unable to Create File from R2 to Openai

await env.DOC_BUCKET.put(id, trainingStr);

const obj = await env.DOC_BUCKET.get(id);

const blob = await obj.blob();
const file = await toFile(blob, obj.key);

const fileCreationResponse = await openai.files.create({
  file,
  purpose: "fine-tune",
});