Instagram getting Access token Notice: Undefined index: access_token

Question

I'm beginner programmer

to get Instagram Authentication, I uploaded this php code on my server

<?php 

getAccessToken();

function getAccessToken(){

if($_GET['code']) {
    $code = $_GET['code'];
    $url = "https://api.instagram.com/oauth/access_token";
    $access_token_parameters = array(
            'client_id'                =>     'b7f14786b7754f04aa43dcxxxxxxxxxx', // my client id
            'client_secret'            =>     '33987fcae22949a9b3682bxxxxxxxxxx', // secret key
            'grant_type'               =>     'authorization_code',
            'redirect_uri'             =>     'http://thedreamkr.com/',
            'code'                     =>     $code
    );
    $curl = curl_init($url);    // we init curl by passing the url
    curl_setopt($curl,CURLOPT_POST,true);   // to send a POST request
    curl_setopt($curl,CURLOPT_POSTFIELDS,$access_token_parameters);   // indicate the data to send
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);   // to return the transfer as a string of the return value of curl_exec() instead of outputting it out directly.
    curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);   // to stop cURL from verifying the peer's certificate.
    $result = curl_exec($curl);   // to perform the curl session
    curl_close($curl);   // to close the curl session

    $arr = json_decode($result,true);
    echo "access_Token: ".$arr['access_token']; // display the access_token
    echo "<br>";   
    echo "user_name : ".$arr['user']['username'];   // display the username
}
}

?>

and when I access to " https://api.instagram.com/oauth/authorize/?client_id=CLIENT-ID&redirect_uri=REDIRECT-URI&response_type=code "

it returns following error

Notice: Undefined index: access_token in /home/ubuntu/php/hashberry/token.php on line 26 
access_Token:
Notice: Undefined index: user in /home/ubuntu/php/hashberry/token.php on line 28
user_name : 

Answer 1

After testing, your code works perfectly.

However: 1- You need to have your code inside of the redirect URI which is different from your website URI. 2- Change your redirect uri to match the one in your registered app.

For example : Website URI: https://example.com/
Redirect URI: https://example.com/register/

Good luck