Fix Meta Pixel + Conversions API tracking on two Shopify stores (one headless build)

I run two ecommerce stores that both have Meta (Facebook) tracking issues. I need an expert in Meta Pixel, Conversions API and Shopify to diagnose and fully fix both, then prove they work with test purchases. **Store 1: Headless frontend built on Lovable, Shopify checkout** The storefront is a custom site built on Lovable (React), integrated with Shopify which handles the checkout. The base Meta Pixel fires PageView from the frontend, but that is all it has ever sent. No ViewContent or AddToCart events exist anywhere. Checkout events (InitiateCheckout, AddPaymentInfo, Purchase) were briefly flowing via the official Facebook & Instagram app on Shopify, through both the browser and the Conversions API. Then they stopped completely at a specific point in time and nothing checkout related has been received since, from browser or server. Real purchases are happening and not reaching Meta. I have already uninstalled and reinstalled the Facebook & Instagram app, confirmed data sharing is set to Maximum, and placed a test order. The test order produced zero events. I suspect the app may now be connected to the wrong pixel or Business Manager, but I need someone to properly diagnose it. What I need on this store: 1. Restore full checkout event tracking (browser and Conversions API) to the correct pixel 2. Add ViewContent and AddToCart events to the Lovable frontend with correct product ID and value parameters 3. Check the domain handoff between the custom frontend and Shopify checkout so click attribution (fbclid / fbp) survives the redirect 4. Verify with a test purchase showing Purchase arriving via both browser and server, correctly deduplicated and attributing in Ads Manager **Store 2: Standard Shopify store** Normal Shopify store, official Facebook & Instagram app installed, data sharing on Maximum. Purchase events are now arriving from both browser and server, but they are not deduplicating. One order shows as two purchases in Events Manager and Ads Manager, so all revenue reports at double. I have tried toggling data sharing off and on. I need the event ID matching fixed so one order equals exactly one reported purchase, and a check that no leftover duplicate pixel exists in theme code or Customer Events. **Deliverables** 1. Both stores tracking Purchase reliably via browser and Conversions API 2. Deduplication verified on both (one test order = one reported purchase, correct value) 3. Full funnel events on the headless store (PageView, ViewContent, AddToCart, InitiateCheckout, Purchase) 4. Short written summary of what was wrong and what you changed, so my team can maintain it **Requirements** 1. Proven experience with Meta Pixel + Conversions API on Shopify, ideally including headless or custom storefront setups 2. Comfortable working in Events Manager, Shopify admin and frontend code (React) 3. Available to start within 24 to 48 hours I will provide collaborator access to both Shopify stores and appropriate access to the Meta assets. Please start your proposal with the word CAPI so I know you read this, and briefly describe a similar deduplication or headless tracking issue you have fixed.