FlutterFlow Checkout RPC Integration -- 2

My FlutterFlow app already lists the services a customer selects; what’s missing is the action behind the “Checkout” button. I need the button custom action that triggers a Supabase RPC and passes a JSON cart of items.

Here’s what I need you to do:
• Build the Dart-based custom action in FlutterFlow, mapping the current cart state to the required JSON structure.
• Trigger an existing (or, if faster, a lightweight new) Supabase RPC that will receive that payload and return a simple success / error response.
• No email or in-app notifications are necessary after the call—just propagate the RPC result so I can display a confirmation screen, toast, or error message inside the app.


If you’ve already connected FlutterFlow apps to Supabase functions, this should be a quick win—we can hop on a short call to hand over credentials and schema details once you’re ready.