I'm trying to send a message to the user as soon as they click on the chat button on my Customer Chat Plugin, what I want to achieve is exactly the flow from this website: mobile monkey
The flow is:
log into messenger
I can't find any example on how to send the user this message without the user sending a message first. To send a message I need the PSID for the user in my php service, but I can't get any response on the user login.
Also, is there any way I can get that PSID on my frontend? What I'm developing requires the bot to ask questions when there is some user action on my website.
edit: Just to be clear, it is not the greeting message, it is and actual message when the chat window opens, see ref.
Ended up finding the answer, just had to use a postback
webhook.
More info here : https://developers.facebook.com/docs/messenger-platform/reference/webhook-events/messaging_postbacks