For Carousel ads, you have to to add a URL Parameter for each of the cards on the Carousel ad.

Inside the FB Ads manager, navigate to the ad level and select the Carousel ad that you want to track with Cometly. There should be a section titled "Ad Creative" with a section for "Carousel Cards".

Each Carousel card will have its own box for "Website URL". Simply past the Cometly URL parameters at the end of the Website URL for each individual carousel card in the ad.

Example:

Below is an example URL on your Carousel ad

https://www.example.com/start

You would need to add:

?comet_source={{site_source_name}}&comet_ad_id={{ad.id}}&comet_placement={{placement}}

If you have a variant URL then you need to append the parameter, see below.

Variant URL Example:

If your Website URL on your Facebook ad is:

www.test.com?variant=123456

Then instead of adding:

?comet_source={{site_source_name}}&comet_ad_id={{ad.id}}&comet_placement={{placement}}

You would need to add:

&comet_source={{site_source_name}}&comet_ad_id={{ad.id}}&comet_placement={{placement}}

So your final Website URL would be:

www.test.com?variant=123456&comet_source={{site_source_name}}&comet_ad_id={{ad.id}}&comet_placement={{placement}}

Also, if you are using a link to your website in the Website URL box in the destination section of the ad, make sure you add the Cometly UTM parameters to the end of that website URL as well.

Before you publish the ad, make sure this area on the ad level is completely EMPTY like in the screenshot below:

Now you can go ahead and publish your ad. As long as you use this setup process on EVERY ad, your tracking and attribution with Cometly will be PERFECT.