getPricesLastDays.js

async function getPricesLastDays(days) {
    try {
        const result = await fetch(`https://api.gold/price?days=${days}`);
        const prices = await result.json();

        const sum = prices.reduce((total, currentValue) => total + currentValue, 0);
        const average = sum / prices.length;

        return { average: +average.toFixed(2) };
    } catch (error) {
        // handle error
        return null;
    }
}