Send server-side conversion events to Meta Conversions API (CAPI)

Steps

1. Generate a System User access token in Meta Business Manager with the ads_management and business_management permissions and store it server-side
2. Collect event parameters server-side at conversion time: event_name, event_time (Unix timestamp), event_source_url, and user_data fields (em, ph, client_ip_address, client_user_agent) hashed with SHA-256 where required
3. POST to the Graph API events endpoint at /{pixel_id}/events using the current Graph API version (v22.0 or later) with the event payload and your access token
4. Include an event_id field that matches the event_id set in the browser Pixel to enable deduplication across client-side and server-side hits
5. Use the test_event_code parameter (available in Events Manager) during development to validate that events appear in the Test Events tool before going to production
6. Monitor the Diagnostics panel in Events Manager for data quality scores and resolve any missing required parameters reported there