Vowel count with async function

vowelCount.js

const vowels = ["a", "e", "i", "o", "u"]

function vowelCount(text, callback) {
    const letters = text.split('')

    const vowelCount = letters.reduce((acc, value) => {

        const isVowel = vowels.includes(value.toLowerCase())
        if (isVowel) acc++

        return acc
    }, 0)

    return callback(vowelCount)
}

function print(value) {
    console.log('result: ', value)
}

vowelCount('thiego', print)