BigCommerce OAuth "Invalid scope" error - php

Question

I'm attempting to retrieve an access token from BigCommerce. I'm following the instructions on this page: https://developer.bigcommerce.com/apps/callback
When I try to retrieve the access token, I am getting an invalid scope error. Here's the code:
public function access_token_get(){
print_r($_GET);
$tokenUrl = "https://login.bigcommerce.com/oauth2/token";
$connection = new Connection();
$connection->setCipher('RC4-SHA');
$connection->verifyPeer(false);
$response = $connection->post($tokenUrl, array(
"client_id" => "123456",
"client_secret" => "123456",
"redirect_uri" => "https://my-registered-auth-callback.com/",
"grant_type" => "authorization_code",
"code" => urlencode($_GET['code']),
"scope" => urlencode($_GET['scope']),
"context" => urlencode($_GET['context'])
));
print_r($response);
print_r($connection->getLastError());
$token = $response->access_token;
print_r($token);
}
When this code runs, I get an empty $response. I added the getLastError() line to see what was going on, and it's outputting:
stdClass Object ( [error] => Invalid scope(s). )
These are the parameters output from the GET request:
Array ( [code] => 2idy1ozvee8s0ddlbg3jgquzgtr55gd [context] => stores/xxxxxx [scope] => store_v2_orders store_v2_products store_v2_customers store_v2_content store_v2_marketing store_v2_information_read_only users_basic_information )
Why would I be receiving this "invalid scopes" error? I also tried hardcoding a single scope to see if that works, for example, just doing "scope"=>"store_v2_orders", but when I do this, I get an error saying that the scope has not been granted by the user.

Answer 1

Looks like the issue was that I did not need to urlencode the code, scope, and context. Removing the urlencode function fixed the issue.