View file ProForum/Files/application/app/Http/Controllers/Gateway/PaypalSdk/Core/RefreshTokenRequest.php

<?php

namespace App\Http\Controllers\Gateway\PaypalSdk\Core;

use App\Http\Controllers\Gateway\PaypalSdk\PayPalHttp\HttpRequest;

class RefreshTokenRequest extends HttpRequest
{
    public function __construct(PayPalEnvironment $environment, $authorizationCode)
    {
        parent::__construct("/v1/identity/openidconnect/tokenservice", "POST");
        $this->headers["Authorization"] = "Basic " . $environment->authorizationString();
        $this->headers["Content-Type"] = "application/x-www-form-urlencoded";
        $this->body = [
            "grant_type" => "authorization_code",
            "code" => $authorizationCode
        ];
    }
}