How to save a csv file with correct encoding using capacitor

I have a nuxt app and using capacitor to create a mobile version app. Currently I want to save a csv file in mobile app (android). Here is my implementation so far:

const csvData = [
    ["創建日期", "賬目類型", "標題"],
    ["2024-03-22", "收入", "發票測試2"]
];

// Convert the CSV data to a CSV string
const csvString = csvData.map(row => row.join(',')).join('n');

// Write the encoded data to a file
const filename = 'data.csv';
const file = await Filesystem.writeFile({
    path: filename,
    data: csvString,
    directory: Directory.Documents,
    encoding: Encoding.UTF8
});

await FileOpener.open({
    filePath: file.uri,
    contentType: 'text/csv',
});

The output csv result doesn’t encoded correctly like this :

Anyone can help?