title: Telethon Error: Can not add user to group using AddChatUserRequest(), Invalid object ID for a chat
body: <p>I tried to use the telethon to develop a telegram bot, when I used AddChatUserRequest to add a user to a group</p>
  
  <pre><code>client(AddChatUserRequest(1168070860, user.id, fwd_limit=10))
  </code></pre>
  
  <p>I met the error:</p>
  
  <blockquote>
    <p>telethon.errors.rpcerrorlist.ChatIdInvalidError: Invalid object ID for
    a chat. Make sure to pass the right types, for instance making sure
    that the request is designed for chats (not channels/megagroups) or
    otherwise look for a different one more suited\nAn example working
    with a megagroup and AddChatUserRequest, it will fail because
    megagroups are channels. Use InviteToChannelRequest instead (caused by
    AddChatUserRequest)</p>
  </blockquote>
  
  <p>I used these code to get the group's information:</p>
  
  <pre><code>chats = client(GetDialogsRequest(
               offset_date=None,
               offset_id=0,
               offset_peer=InputPeerEmpty(),
               limit=200,
               hash = 0
           )).chats
  
  groups = []
  for chat in chats:
      try:
          if chat.megagroup == True:
              groups.append(chat)
              print(chat.title,chat.id)
      except:
          continue
  </code></pre>
  
  <p>And here's the group's information that I tried to add user:</p>
  
  <pre><code>Channel(left=False, id=1168070860, banned_rights=None, title='ruby and his friends', version=0, verified=False, signatures=False, broadcast=False, participants_count=None, creator=True, has_geo=False, photo=ChatPhoto(dc_id=1, photo_small=FileLocationToBeDeprecated(local_id=270793, volume_id=806122192), photo_big=FileLocationToBeDeprecated(local_id=270795, volume_id=806122192)), username='lanlugroup', megagroup=True, restricted=False, default_banned_rights=ChatBannedRights(change_info=True, until_date=datetime.datetime(2038, 1, 19, 3, 14, 7, tzinfo=datetime.timezone.utc), send_inline=False, invite_users=False, pin_messages=True, send_media=False, send_gifs=False, send_games=False, embed_links=False, send_stickers=False, send_messages=False, view_messages=False, send_polls=False), restriction_reason=None, min=False, has_link=False, scam=False, date=datetime.datetime(2019, 4, 1, 12, 44, 47, tzinfo=datetime.timezone.utc), admin_rights=None, access_hash=-5901560198799322202)
  </code></pre>
  
  <p>I used the id 1168070860 as the chat_id in AddChatUserRequest</p>
  
  <p>(BTW, I login with the phone number as a normal user, not as a bot)</p>