For Carousel ads, you have to to create 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". Underneath that box, there is a line of blue text labeled "Build a URL Parameter". Click that to open up a popup (displayed below):
First click into the first box for Campaign source, and type in "Facebook" here.
Then, click into any of the 3 text boxes on this popup (it does not matter which one) to reveal a dropdown. From the dropdown, make sure you select the {{ad.id}} option.
If all of these boxes are already being used for other parameters, no worries! You can click the box that says "Add parameter" and type in "utm_term" in the box for "Parameter name" and {{ad.id}} for the box for "Value".
If you are already using utm_term and you definitely do not want to change any of them, you can also use the custom parameter "ref". We do not recommend using this parameter because you will not be able to see any "ref" UTMs in Shopify Reports, so there is no way for you to audit this data to see how much Cometly is helping your tracking :). However, if you still want to use "ref", set up the parameter like we have pictured below. Just type in "ref" in the box for "Parameter name" and {{ad.id}} for the box for "Value".
After you click apply your Website URL should now contain the proper UTM parameters set up as shown in the screenshot below:
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.
For any remaining ads that do not use carousel ads, return to the main article How to ensure your UTMs are set up perfectly.