Get username in custom script that works with amember_remote (for V4)

So I have a plugin that works with amember_remote for v3. Here is a part of a code that needs to be changed.

Code:

if(is_file($vars)){
    include('config.inc.php');
    $_amember_id = $_SESSION['_amember_id'];
    $info = pathinfo($vars);
    $ref = $_SERVER["HTTP_REFERER"];
    $ref = explode('/', trim($ref,'/'));
    $text = $_SESSION['_amember_remote_login'].'<br>'.$ref[2].'<br>'.date('d.m.y H:i:s').'<br>'.$_SERVER['REMOTE_ADDR'];
    $text = base64_encode($text);

So here we get a username and then do some manipulations with it. V4 is very different and uses API, maybe there is a easy way to change that part for V4.