> ## Documentation Index
> Fetch the complete documentation index at: https://docs.invoca.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Why Isn't the Facebook Click ID Being Captured?

> Create a Marketing Data field for the Facebook Click ID (`_fbc`) and update your Invoca Tag to capture it from a cookie, then reference it in your Conversions API events.

**Applies to:** Facebook Conversions API (CAPI)

## Symptoms

The Facebook Click ID (`_fbc`) isn't included in the data Invoca sends to Facebook's Conversions API.

## Resolution

1. Create a custom Marketing Data field for the Facebook Click ID:
   * **Type:** Short Text
   * **Partner (API) Name:** `_fbc`
   * **Friendly Name:** Facebook Click ID
   * **Attribution model:** Last
2. Update your Invoca Tag to capture the Facebook Click ID from a cookie:
   * **Data Source:** Cookie, pointing to the `_fbc` cookie.
3. When configuring your "Send Call Events" or "Send Signal Events" Action, click **+ Add Values** under Additional User Data, then:
   * Enter `fbc` in the Additional User Data Name field.
   * Enter the substitution token `<_fbc>` in the Additional User Data Value field.

## Where to go next

* [Why Is Data Failing to Reach Facebook?](/s/article/facebook-data-failures)