Конвертер валют

<div class="container">
<h2>Конвертер валют</h2>
<p>Последнее обновление: <b class="date">26.03.2020 18:35:57</b></p>
<div class="group">
    <input type="number" class="first-input">
    <select class="first-select"></select>

    <input type="number" class="second-input">
    <select class="second-select"></select>
</div>

<script src="https://cdnjs.cloudflare.com/ajax/libs/axios/0.19.2/axios.min.js"></script>

<script>
const container = document.querySelector('.container .group');
const currencyDate = document.querySelector('.container .date');

const firstInput = container.querySelector('.first-input');
const secondInput = container.querySelector('.second-input');

const firstSelect = container.querySelector('.first-select');
const secondSelect = container.querySelector('.second-select');

firstInput.addEventListener('input', () => firstHandle());
secondInput.addEventListener('input', () => secondHandle());

firstSelect.addEventListener('change', () => firstHandle());
secondSelect.addEventListener('change', () => secondHandle());

const firstHandle = () => {
    const value = firstInput.value;
    const currency = firstSelect.options[firstSelect.selectedIndex].dataset.currency;
    secondInput.value = value * currency;
}
const secondHandle = () => {
    const value = secondInput.value;
    const currency = secondSelect.options[secondSelect.selectedIndex].dataset.currency;
    firstInput.value = value * currency;
}

const handleInput = () => {
    const first = firstSelect.options[firstSelect.selectedIndex].dataset.currency;
    const second = secondSelect.options[secondSelect.selectedIndex].dataset.currency;
    
    firstInput.value = 1;
    firstHandle();
};

const handleRequest = ({ data }) => {
    const date = new Date(data.PreviousDate);
    const optionsDateFormat = {
        year: 'numeric',
        month: '2-digit',
        day: '2-digit',
        hour: 'numeric',
        minute: 'numeric',
        second: 'numeric'
    };
    
    currencyDate.innerHTML = date.toLocaleDateString('ru-RU', optionsDateFormat);


    Object.values(data.Valute).forEach(valute => {
        const option = document.createElement('option');
        const option2 = document.createElement('option');
        
        option.innerHTML = valute.Name;
        option.dataset.currency = Cur_OfficialRate;
        if (Cur_OfficialRate === 'EUR')
            option.selected = true;
            
        option2.innerHTML = valute.Name;
        option2.dataset.currency = Cur_OfficialRate;
        if (Cur_OfficialRate === 'BYN')
            option2.selected = true;
            
        firstSelect.append(option);
        secondSelect.append(option2);
    });
    
    handleInput();
}

const options = {
    headers: { 'Content-Type': 'application/json' }
}
axios.get('https://www.nbrb.by/api/exrates/rates?periodicity=0', options)
    .then(handleRequest).catch();
</script>