Hi friends, I've been using ManyChat for a while to automatically answer comments and send links to DMs. 

But I haven't yet reached the next step of following up by offering those who messaged to opt in for individual broadcasts  (I.E. once they've opted in, I can send people DMs when there's an exciting announcement).

I can't find out how to send people a follow up message asking them to sign up for my ManyChat DMs

I got as far as Instagram Settings -> Opt-in Automation -> I set a trigger word "subscribe" -> I automatically send people a DM saying they're subscribed to receive our broadcasts -> But I don't think anything actually happens... I haven't cracked the middle part which is to "Set Instagram Opt-In"... Help?