diff --git a/telethon/_client/auth.py b/telethon/_client/auth.py
index 2a3e3af3..ff03d92d 100644
--- a/telethon/_client/auth.py
+++ b/telethon/_client/auth.py
@@ -267,7 +267,7 @@ async def sign_up(
 
     result = await self(_tl.fn.auth.SignUp(
         phone_number=phone,
-        phone_code_hash=phone_code_hash,
+        phone_code_hash=self._phone_code_hash,
         first_name=first_name,
         last_name=last_name
     ))
diff --git a/telethon/_client/updates.py b/telethon/_client/updates.py
index 9882cf0a..d86c3e09 100644
--- a/telethon/_client/updates.py
+++ b/telethon/_client/updates.py
@@ -2,6 +2,7 @@ import asyncio
 import inspect
 import itertools
 import random
+import functools
 import sys
 import time
 import traceback
@@ -225,7 +226,7 @@ class Entities:
         self._client = client
         self._entities = {e.id: e for e in itertools.chain(
             (User._new(client, u) for u in users),
-            (Chat._new(client, c) for u in chats),
+            (Chat._new(client, c) for c in chats),
         )}
 
     def get(self, peer):
diff --git a/telethon/_events/chataction.py b/telethon/_events/chataction.py
index 435ab459..c8a6f849 100644
--- a/telethon/_events/chataction.py
+++ b/telethon/_events/chataction.py
@@ -13,6 +13,7 @@ class ChatAction(EventBuilder):
     * Whenever a new message is pinned.
     * Whenever a user scores in a game.
     * Whenever a user joins or is added to the group.
+    * Whenever a new chat join request is sent.
     * Whenever a user is removed or leaves a group if it has
       less than 50 members or the removed user was a bot.
 
@@ -48,6 +49,9 @@ class ChatAction(EventBuilder):
             `True` if the user's join request was approved.
                 along with `user_joined` will be also True.
 
+        new_join_request (:tl:`ExportedChatInvite`, optional):
+            Chat Invite, if the new chat join request was sent (Only Bots get this Update).
+
         created (`bool`, optional):
             `True` if this chat was just created.
 
@@ -80,6 +84,7 @@ class ChatAction(EventBuilder):
         kicked_by = None
         created = None
         from_approval = None
+        new_join_request = None
         users = None
         new_title = None
         pin_ids = None
@@ -109,6 +114,11 @@ class ChatAction(EventBuilder):
             kicked_by = True
             users = update.user_id
 
+        elif isinstance(update, _tl.UpdateBotChatInviteRequester):
+            users = update.user_id
+            where = _tl.PeerChat(update.chat_id)
+            new_join_request = update.invite
+
         # UpdateChannel is sent if we leave a channel, and the update._entities
         # set by _process_update would let us make some guesses. However it's
         # better not to rely on this. Rely only in MessageActionChatDeleteUser.
@@ -161,11 +171,14 @@ class ChatAction(EventBuilder):
                 new_photo = True
             elif isinstance(action, _tl.MessageActionPinMessage) and msg.reply_to:
                 where = msg
-                pin_ids=[msg.reply_to_msg_id]
+                pin_ids=[msg.reply_to.reply_to_msg_id]
             elif isinstance(action, _tl.MessageActionGameScore):
                 where = msg
                 new_score = action.score
-
+            else:
+                return
+        else:
+            return
         self = cls.__new__(cls)
         self._client = client
 
@@ -196,6 +209,7 @@ class ChatAction(EventBuilder):
             self.user_added = True
             self._added_by = added_by
         self.user_approved = from_approval
+        self.new_join_request = new_join_request
 
         # If `from_id` was not present (it's `True`) or the affected
         # user was "kicked by itself", then it left. Else it was kicked.
@@ -290,6 +304,17 @@ class ChatAction(EventBuilder):
 
         return self._pinned_messages
 
+    async def approve_user(self, approved: bool = True):
+        """
+        Approve or disapprove chat join request of user.
+        """
+        if self.new_join_request:
+            return await self._client(_tl.fn.messages.HideChatJoinRequest(
+                await self.get_input_chat(),
+                user_id=self.user_id,
+                approved=approved
+            ))
+
     @property
     def added_by(self):
         """
diff --git a/telethon/types/_custom/chat.py b/telethon/types/_custom/chat.py
index f5056eff..2e4ac14c 100644
--- a/telethon/types/_custom/chat.py
+++ b/telethon/types/_custom/chat.py
@@ -2,6 +2,8 @@ from typing import Optional, List, TYPE_CHECKING
 from datetime import datetime
 from dataclasses import dataclass
 import mimetypes
+
+from ..._sessions.types import Entity
 from .chatgetter import ChatGetter
 from .sendergetter import SenderGetter
 from .messagebutton import MessageButton