# Connect Reverse ETL Source to Snapchat Custom Audience

This guide takes you through the steps to connect a Reverse ETL source to the Snapchat Custom Audience destination.

## Set up the connection 

{{< warning >}}
**The Reverse ETL feature supports only source-driven pipeline configuration.**

Make sure you have [set up a RETL source]({{< ref "sources/reverse-etl/_index.md" >}}) and connected it to your Snapchat Custom Audience destination before following the below steps.
{{< /warning >}}

1. [Confirm the connection settings]({{< ref "destinations/reverse-etl-destinations/snapchat-custom-audience/setup-guide.md#connection-settings" >}}) for your Snapchat Custom Audience destination and click **Continue**.

2. In the **Where do you want to sync data to?** section, select the **Object**.

{{< image src="images/event-stream-destinations/snapchat-custom-audience-retl-settings-2.webp" >}}

3. Set the [Sync mode]({{< ref "data-pipelines/reverse-etl/developer-guides/sync-modes.md" >}}) to specify how RudderStack should sync the data to Snapchat Custom Audience.
4. In **Choose identifier**, specify the warehouse column that RudderStack uses to identify your records.

{{< warning >}}
Choose the same field that you set as the **Schema** while configuring your Snapchat Custom Audience destination. For more information, see the **Schema** setting in the [Setup guide]({{< ref "destinations/reverse-etl-destinations/snapchat-custom-audience/setup-guide.md#connection-settings" >}}).
{{< /warning >}}

{{< image src="images/event-stream-destinations/snapchat-custom-audience-identifier.webp" >}}

5. Map your warehouse columns to specific Snapchat Custom Audience fields using the **Map fields** setting.

{{< image src="images/event-stream-destinations/snapchat-custom-audience-map-fields.webp" >}}


## FAQ

#### Why can't I add a Reverse ETL source from the destination page?

The Reverse ETL feature supports only source-driven pipeline configuration. It means that you must configure a Reverse ETL source in RudderStack and then connect it to a new or existing destination. Note that this destination should not be connected to any other source.

See [Reverse ETL FAQ]({{< ref "data-pipelines/reverse-etl/developer-guides/faq.md" >}}) for more information.

#### How do I view the synced segments in Snapchat Custom Audience?

1. Log in to your [Snapchat Ad Manager](https://ads.snapchat.com/).
2. Click **Audiences**.

{{< image src="images/event-stream-destinations/snapchat-custom-audience-synced-segments-1.webp" >}}

In the resulting view, you can see the audience and number of synced users.

{{< image src="images/event-stream-destinations/snapchat-custom-audience-synced-segments-2.webp" >}}

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