Hello ​@massimog ,
To add a new question to a flow, click the "+" button and select the channel that will send the content (Instagram, WhatsApp, or others).
The Manychat help article below provides a more detailed overview and a step-by-step guide to creating your first automation:
https://help.manychat.com/hc/en-us/articles/14281166306332-How-to-build-a-Manychat-automation#h_01JDSRVYEHHVBSP6CG755BNCYM
Feel free to send a screenshot if you're having trouble with a specific content block.

Let me know if you're able to move forward.

Hi ​@rogerioaraujo 

Sorry I meant to say Answer instead of Question. However I followed your advise and I went ahead creating a new Messenger button but the system creates a new button outside of the current answers list. Instead I need this new button to be added to the current answer list. Any idea?

Hello ​@massimog ,
To add buttons to an existing message in Messenger, simply click the option highlighted in the screenshot below.
 

If you're using a different channel or have any other questions, feel free to send a screenshot as well.

Let me know if you still need help.