Laravel phpunit test failing authorization

php laravel laravel-5.6

PHP Snippet 1:

$response = $this->json('POST', '/api/books', [
            'title' => 'book post',
            'author' => 'post author'
        ],['Authorization' => "Bearer $token"]);

PHP Snippet 2:

 $response = $this->post('/api/books', [
            'title' => 'book post',
            'author' => 'post author'
        ],['Authorization' => "Bearer $token"]);