Expected file to have JSONL format, where every line is a JSON dictionary. openai createFile for fine tune

I created file with name mydata.jsonl and I put on it these lines

    {
        "prompt": "aa",
        "completion": "bb"
    }
    {
        "prompt": "cc",
        "completion": "dd"
    }

then in index.js I did this function

    const { Configuration, OpenAIApi } = require("openai");
    const fs = require("fs");
    
    const configuration = new Configuration({
        apiKey: process.env.OPENAI_API_KEY,
    });
    async function getAiResponse(topic) {
        const openai = new OpenAIApi(configuration);
        const filename = 'example.txt';
        const fileContents = 'This is some example text.';
        const response = await openai.createFile(
            fs.createReadStream("mydata.jsonl"),
            "fine-tune"
        );
        console.log(response)
    }
    getAiResponse("ee");

when I run my code I got error

    Expected file to have JSONL format, where every line is a JSON dictionary. Line 1 is not a dictionary (HINT: line starts with: "{...").

I can't get where is the exactly the error

The JSONL format is where the each json object is sperated by a newline characater.

So your output should be:

{ "prompt": "aa", "completion": "bb" }
{ "prompt": "cc", "completion": "dd" }

i.e. one LINE per json object