Add notification to stage instance creation

discord/channel.py

@@ -1263,6 +1263,7 @@ async def create_instance(
         topic: str,
         privacy_level: StagePrivacyLevel = MISSING,
         reason: Optional[str] = None,
+        send_notification: Optional[bool] = False,
     ) -> StageInstance:
         """|coro|
 
@@ -1281,6 +1282,9 @@ async def create_instance(
             The stage instance's privacy level. Defaults to :attr:`StagePrivacyLevel.guild_only`.
         reason: :class:`str`
             The reason the stage instance was created. Shows up on the audit log.
+        send_notification: :class:`bool`
+            Send a notification to everyone in the server that the stage instance has started.
+            Defaults to ``False``. Requires the ``mention_everyone`` permission.
 
         Raises
         ------
@@ -1297,7 +1301,7 @@ async def create_instance(
             The newly created stage instance.
         """
 
-        payload: Dict[str, Any] = {"channel_id": self.id, "topic": topic}
+        payload: Dict[str, Any] = {"channel_id": self.id, "topic": topic, "send_start_notification": send_notification}
 
         if privacy_level is not MISSING:
             if not isinstance(privacy_level, StagePrivacyLevel):

discord/http.py

@@ -1907,9 +1907,13 @@ def create_stage_instance(self, *, reason: Optional[str], **payload: Any) -> Res
             "channel_id",
             "topic",
             "privacy_level",
+            "send_start_notification",
         )
         payload = {k: v for k, v in payload.items() if k in valid_keys}
 
+        if payload.get("send_start_notification") is not None:
+            payload["send_start_notification"] = int(payload["send_start_notification"])
+
         return self.request(Route("POST", "/stage-instances"), json=payload, reason=reason)
 
     def edit_stage_instance(