First of all a room creator sends the new `m.room.poll_history` state event in the `initial_state` when calling the [createRoom API](https://spec.matrix.org/v1.6/client-server-api/#post_matrixclientv3createroom).
First of all a room creator sends the new `m.room.poll_history` state event in the `initial_state` when calling the [createRoom API](https://spec.matrix.org/v1.6/client-server-api/#post_matrixclientv3createroom).