Graph API Facebook SDK for PHP Permissions Error

I am working on Auto Posting on facebook page or group by using graph api. But i get error of permissions but i allow permissions But i face this error. Any one who know about this error.
Code given below.
I share some images Which error showing me or how to allow permissions.

<?php

    require_once ('vendor/autoload.php');

    $fb = new FacebookFacebook([
        'app_id' => '{app-id}',
        'app_secret' => '{app-secret}',
        'default_graph_version' => 'v2.10',
    ]);

    $pageAccessToken = '{page-access-token}';

    $MsgData = [
        'message' => 'Hi, My name is Zaheer'
    ];

    try {
        $response = $fb->post('/me/feed/' , $MsgData , $pageAccessToken );
    }
    catch ( FacebookExceptionsFacebookResponseException $e ) {
        echo 'Graph returned an error ' . $e->getMessage();
        exit;
    }

    $GraphNode = $response->getGraphNode();

    echo 'ID :' . $GraphNode['id'];


    ?>