title: Adding user to Twilio channel.
body: <p>Is there a way of adding a user to a Twilio channel using the REST API?</p>
  
  <pre><code>from twilio.rest import Client
  
  # Initialize the client
  account = "ACXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
  token = "your_auth_token"
  client = Client(account, token)
  
  # Update the channel
  user = client.chat \
                  .services("ISXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX").users.list()[0]
  channel = client.chat \
                  .services("ISXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX") \
                  .channels("CHXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX").list()[0]
  # How to add user to channel?
  </code></pre>