Guzzle Laravel simple connection and errors checker

Im using Guzzle on a laravel Project, Im want to have a working connection validation and error checker if has errors, also want first check the connection if its 200 if isnt then show the error message, if is 200 then proceed to second check that checking if has Error from the remote server like "duplicate ID" if has no error then make the POST or GET request is it possible that? because now when run this get error on $errormsg

My function:

  public function showinvoice()
    {
        $client = new \GuzzleHttp\Client([
            'http_errors' => false,
            'headers' => [
                'aade-user-id' => 'blabla',
                'Ocp-Apim-Subscription-Key' => 'blablabla',
               
            ]
        ]);

        $request = $client->GET('https://mydatapi.aade.gr/myDATA/RequestMyExpenses/?dateFrom=11/11/2021&dateTo=11/12/2022');

        $response = $request->getBody()->getContents();

        $reasonPhrase = $request->getReasonPhrase();

        $statusCode = $request->getStatusCode();
        $errormsg = strval(simplexml_load_string($response)->response->errors->error->message);
        if ($statusCode <= 200) { 

            if (isset($errormsg)) {

                $this->dispatchBrowserEvent('alert', ['type' => 'error', 'message' => $errormsg]);
            }
            else{
               return $response;
            }
   
        } 
        else {
            $this->dispatchBrowserEvent('alert', ['type' => 'error', 'message' => $statusCode .' '. $reasonPhrase]);
        }
    }
    ```

via Chebli Mohamed