What is when does the typing notification appear on snapchat?

As an AI language model, I don't have access to the current Snapchat application settings and features. However, typically, when you are in a chat with a friend or a group, and someone is typing a message to you, you will see a small "typing" notification appear on the chat screen. This indicates that the person is actively writing a message. The typing notification disappears when the message is sent or the person stops typing. It helps to know when someone is composing a message and when you can expect a response.