error.txt

{"error":"invalid_client","message":"Client authentication failed"}

passport values.txt

id: 3
token: 9obelPLLNTDvHTdbS5ZuLYCDqNw6PkNc4Opi6JJj

route.php

<?php

/*
|--------------------------------------------------------------------------
| Web Routes
|--------------------------------------------------------------------------
|
| This file is where you may define all of the routes that are handled
| by your application. Just tell Laravel the URIs it should respond
| to using a Closure or controller method. Build something great!
|
*/

use Illuminate\Http\Request;

// First route that user visits on consumer app
Route::get('/', function () {
    // Build the query parameter string to pass auth information to our request
    $query = http_build_query([
        'client_id' => 3,
        'redirect_uri' => 'http://localhost:7000/callback',
        'response_type' => 'code',
        'scope' => '*'
    ]);

    // Redirect the user to the OAuth authorization page
    return redirect('http://localhost:8000/oauth/authorize?' . $query);
});

// Route that user is forwarded back to after approving on server
Route::get('callback', function (Request $request) {
    $http = new GuzzleHttp\Client;

    $response = $http->post('http://localhost:8000/oauth/token', [
        'form_params' => [
            'grant_type' => 'authorization_code',
            'client_id' => '3',
	        'client_secret' => '9obelPLLNTDvHTdbS5ZuLYCDqNw6PkNc4Opi6JJj',
            'redirect_uri' => 'http://localhost:7000/callback',
            'code' => $request->code// Get code from the'
        ]
    ]);

    return json_decode((string) $response->getBody(), true)['access_token'];
});