facebook ads messenger: greeting message / conversation starter doesnt show when user clicks

I have set the Greeting Text, and i have created a  Conversation Starter which leads into an automation, however when i create a Facebook Ad, and select ‘create new’ it forces me to use their default template questions. 

How can I disable that, and make it so if a user clicks Send message on my facebook ad, they will see only the greeting text i set in manychat, followed by the automation which is triggered by the conversation starter?  

Thank you