How can I resolve the error when loading into a frame while running dklab_realplexor?

Question

linux

Please explain and help me solve the issue that arises when installing the dklab_realplexor server. Introduction: the task was to put the version of realplexor c ++ on vds. The realplexor itself stands on realplexor.shyass.space, and the data is caught on shyass.space, respectively. When requested in the console wget realplexor.shyass.space everything is fine.
But when trying to send and receive data

<? 
require_once "Realplexor.php";
$rpl = new Dklab_Realplexor(
    "127.0.0.1", 
    "10010",   
    "nsp"   

$rpl->send("Alpha", 'hello');

?>

var realplexor = new Dklab_Realplexor(
    "http://realplexor.shyass.space/",  
    "nsp" 
);

realplexor.subscribe("Alpha", function(data, id) {
    document.getElementById('first').innerHTML += data + "<br>";
});
realplexor.execute();

the following error occurs: Permission denied to access property "Dklab_Realplexor_Loader".
I tried to figure it out - I realized that the matter was in various hosts, but I did not solve this issue. Please help. Thank you all in advance.
PS

// Constructor.
// Create new Dklab_Realplexor object.
function Dklab_Realplexor(fullUrl, namespace, viaDocumentWrite)
{
    // Current JS library version.
    var VERSION = "1.32";

    // Detect current page hostname.
    var host = document.location.host;

    // Assign initial properties.
    if (!this.constructor._registry) this.constructor._registry = {}; // all objects registry
    this.version = VERSION;
    this._map = {};
    this._realplexor = null;
    this._namespace = namespace;
    this._login = null;
    this._iframeId = "mpl" + (new Date().getTime());
    this._iframeTag =
        '<iframe'
        + ' id="' + this._iframeId + '"'
        + ' onload="' + 'Dklab_Realplexor' + '._iframeLoaded(&quot;' + this._iframeId + '&quot;)"'
        + ' src="' + fullUrl + '?identifier=IFRAME&amp;HOST=' + host + '&amp;version=' + this.version + '"'
        + ' style="position:absolute; visibility:hidden; width:200px; height:200px; left:-1000px; top:-1000px"' +
        '></iframe>';
    this._iframeCreated = false;
    this._needExecute = false;
    this._executeTimer = null;

    // Register this object in the registry (for IFRAME onload callback).
    this.constructor._registry[this._iframeId] = this;

    // Validate realplexor URL.
    if (!fullUrl.match(/^\w+:\/\/([^/]+)/)) {
        throw 'Dklab_Realplexor constructor argument must be fully-qualified URL, ' + fullUrl + ' given.';
    }
    var mHost = RegExp.$1;
    if (mHost != host && mHost.lastIndexOf("." + host) != mHost.length - host.length - 1) {
        throw 'Due to the standard XMLHttpRequest security policy, hostname in URL passed to Dklab_Realplexor (' + mHost + ') must be equals to the current host (' + host + ') or be its direct sub-domain.';
    }

    // Create IFRAME if requested.
    if (viaDocumentWrite) {
        document.write(this._iframeTag);
        this._iframeCreated = true;
    }

    // Allow realplexor's IFRAME to access outer window.
    document.domain = host;
}

// Static function.
// Called when a realplexor iframe is loaded.
Dklab_Realplexor._iframeLoaded = function(id)
{
    var th = this._registry[id];
    // use setTimeout to let IFRAME JavaScript code some time to execute.
    setTimeout(function() {
        var iframe = document.getElementById(id);
        th._realplexor = iframe.contentWindow.Dklab_Realplexor_Loader;
        if (th.needExecute) {
            th.execute();
        }
    }, 50);
}

// Set active login.
Dklab_Realplexor.prototype.logon = function(login) {
    this._login = login;
}

// Set the position from which we need to listen a specified ID.
Dklab_Realplexor.prototype.setCursor = function(id, cursor) {
    if (!this._map[id]) this._map[id] = { cursor: null, callbacks: [] };
    this._map[id].cursor = cursor;
    return this;
}

// Subscribe a new callback to specified ID.
// To apply changes and reconnect to the server, call execute()
// after a sequence of subscribe() calls.
Dklab_Realplexor.prototype.subscribe = function(id, callback) {
    if (!this._map[id]) this._map[id] = { cursor: null, callbacks: [] };
    var chain = this._map[id].callbacks;
    for (var i = 0; i < chain.length; i++) {
        if (chain[i] === callback) return this;
    }
    chain.push(callback);
    return this;
}

// Unsubscribe a callback from the specified ID.
// You do not need to reconnect to the server (see execute())
// to stop calling of this callback.
Dklab_Realplexor.prototype.unsubscribe = function(id, callback) {
    if (!this._map[id]) return this;
    if (callback == null) {
        this._map[id].callbacks = [];
        return this;
    }
    var chain = this._map[id].callbacks;
    for (var i = 0; i < chain.length; i++) {
        if (chain[i] === callback) {
            chain.splice(i, 1);
            return this;
        }
    }
    return this;
}

// Reconnect to the server and listen for all specified IDs.
// You should call this method after a number of calls to subscribe().
Dklab_Realplexor.prototype.execute = function() {
    // Control IFRAME creation.
    if (!this._iframeCreated) {
        var div = document.createElement('DIV');
        div.innerHTML = this._iframeTag;
        document.body.appendChild(div);
        this._iframeCreated = true;
    }

    // Check if the realplexor is ready (if not, schedule later execution).
    if (this._executeTimer) {
        clearTimeout(this._executeTimer);
        this._executeTimer = null;
    }
    var th = this;
    if (!this._realplexor) {
        this._executeTimer = setTimeout(function() { th.execute() }, 30);
        return;
    }

    // Realplexor loader is ready, run it.
    this._realplexor.execute(
        this._map,
        this.constructor._callAndReturnException,
        (this._login != null? this._login + "_" : "") + (this._namespace != null? this._namespace : "")
    );
}

// This is a work-around for stupid IE. Unfortunately IE cannot
// catch exceptions which are thrown from the different frame
// (in most cases). Please see
// http://blogs.msdn.com/jaiprakash/archive/2007/01/22/jscript-exceptions-not-handled-thrown-across-frames-if-thrown-from-a-expando-method.aspx
Dklab_Realplexor._callAndReturnException = function(func, args) {
    try {
        func.apply(null, args);
        return null;
    } catch (e) {
        return "" + e;
    }
}

Answer 1

Where exactly does the error occur?

Permission denied to access property "Dklab_Realplexor_Loader"

?