code: protected function getTokenFormApi()
      {
          $http = $this->getHttp();
  
          $token = $http->parseJson($http->post(self::API_TOKEN_URI, [
              'grant_type' => 'client_credentials',
              'client_id'  => $this->getAppKey(),
              'client_secret' => $this->getSecretKey()
          ]));
  
          if (empty($token[$this->tokenSucessKey])) {
              throw new RuntimeException('Request AccessToken fail. response: '.json_encode($token, JSON_UNESCAPED_UNICODE));
          }
  
          return $token;
      }
docs: Get Token From Api.
  
  @throws  \Exception
  
  @return array