If I understand correctly, you want to automatically send a message flow to someone when they interact with your ManyChat automation.
If so, the steps would be:
Set Up a Default Reply: This will trigger the automation flow. (Optional if you already have this set up)
Send a Request to Make.com: In the triggered flow, send a request to Make.com.
Set a Custom Field in Make: When the Make scenario is triggered, set a custom field using a Make module.
Trigger Another ManyChat Automation: Use this custom field to trigger another automation in ManyChat to continue the conversation.
Essentially, you'll use a combination of mini automation flows to loop through and continue the conversation. The default reply will help trigger the automation if users don’t respond predictably to start the ManyChat automation.
I hope this helps! Here is a video that might add context: YouTube Video.