Meta's platform rules dont allow businesses to initiate messages via webhooks on Instagram and Facebook.
How Instagram & Facebook Messaging Works
On these platforms, the customer must start the conversation:
Only a comment or DM from a customer can initiate a response
You cannot send an automated message first to someone's Instagram/Facebook inbox (You can still text them manually whenever you want)
Once they message you, you can reply with automated messages
You can continue automated conversations within the 24 hour messaging window
What This Means for Automation
Scenario: Someone creates an order on your Shopify store.
✅ WhatsApp: Webhook trigger works. You can send order confirmation via WhatsApp.
❌ Instagram/Facebook: No webhook trigger available. The order happened outside Instagram (on your website), and Meta doesnt let you message customers about it unless they contacted you first on Instagram.
The Rule:
If an event happens outside Instagram/Facebook (website purchase, form submission, etc.), you cant use that event to send an Instagram/Facebook message. The interaction must originate from the customer on that platform.
What You CAN Do on Instagram & Facebook
Respond to comments automatically
Reply to DMs when customers message first
Send follow up messages within 24 hours of their last message
Use Instagram comment automation to drive people to DM you
What You CANNOT Do
Send order confirmations via Instagram for Shopify orders
Message customers first about events from external systems
Use webhook triggers to initiate Instagram/Facebook conversations
Bottom line: Webhook flows work great for WhatsApp. For Instagram and Facebook, you need the customer to make the first move on those platforms. Since WhatsApp is a more reliable channel to send updates about orders and other actions taken by the customer, it's better that those messages are sent through WhatsApp.