Make a rights system for commands?

Question

JavaScript

For example, if the user whose id is not recorded in the bot, he will not be able to use it and he will receive an answer about that.
Tried to use Json but didn't work.

vk.updates.hear(/^(?:рассылка)\s?([^]+)?/i,  message => { 
  if(acc.users[user_id(message.user)].level < 4) return;
  for(i in acc.users){
    vk.api.call('messages.send', {
      user_id: acc.users[i].id,
      random_id: 100000000,
      message: `${message.$match[1]}`
    });
  }
  return message.send(`&#9889;Сообщения отправлены!`);
});