There are several prerequisites to building a Messenger chatbot, which we will assume are already taken care of. Before we start, please make sure that you already have:
an active Facebook account
a Facebook page for your chatbot to be associated with that you are an admin of
a CSML chatbot ready to go
In CSML Studio, visit Channels > Connect new channel > Messenger. Click on Continue with Facebook to grant permissions to CSML Studio to connect bots to your chosen pages. This starts a standard Facebook login flow:
After this, simply select the page you want to link to the bot, and wait a few seconds.
Voilà! You can now search for your chatbot in Facebook Messenger (it will be listed under the page's name).