async function getUsername(userId) {
    const cache = _cache.users;
    if (cache[userId]) return cache[userId].name;

    const requestUrl = usernameURL.replace('{userId}', userId);

    const response = await fetch(requestUrl, { method: 'GET' });
    if (!response.ok) {
        throw new Error(response.status + ' ' + response.statusText);
    }
    const data = await response.json();
    cache[userId] = data;

    return data.name;
}
Fetches the username from Panoramax
@param {string} userId
@returns the username