Array to string conversion error in header

Question

Currently working with laravel 8.And calling the api using httpclient but few of them i need to pass the bearer token in headers for which struggling from couple of hours seems like didn't work anything.

Any help will be appreciated. Thanks,

  try {
        $token = array(Session::get('access_token'));
        $headers = [
            'Authorization' => 'Bearer ' . $token,        
            'Accept'        => 'application/json',
        ];
        // echo "<pre>"; print_r($token); die();
        if ( $data != null ) {
            $response = Http::withHeaders($headers)->asForm()->post($endpoint, $data);
        }else{
            $response = Http::get($endpoint);
        }

        $result      = $response->json();
        echo "<pre>"; print_r($result);die();
        $httpcode    = $response->status();

        $error_msg   = ($response->serverError()) ?? '';
        // echo "<pre>"; print_r($result);die();
        if ( $error_msg == '' ) {

            $response = [ 'status' => true, 'result' => $result, 'status_code' => $httpcode ];
            return $response ;
        } else {
            return [ 'status' => false, 'result' => [], 'status_code' => $httpcode, 'error' => $error_msg ];
        }
    }