When connected, a Meta Pixel sends events to the Conversions API Gateway using a domain proper to this communication, ideally the same as the page where the pixel fires (that is, first-party communication). For example, if the pixel fires on advertiser.com, ideally the Conversions API Gateway will be reachable by the pixel on gateway.advertiser.com.
The data routing functionality allows you to define the subdomain for the pixel to communicate with the Conversions API Gateway.
To configure Data routing, select the Data routing menu under Conversions API Gateway.
Click on Optimize to modify the subdomain that the pixel uses to communicate with and send event data to the Conversions API Gateway.
Define the subdomain the pixel should use to communicate with the Conversions API Gateway. It is recommended that the subdomain be based on the same domain as the website firing the pixel.
Create the CNAME records on the DNS provider managing the new domain. The page will auto-refresh after about 30 minutes of setting up the DNS records. The new subdomain will be configured and data routing shows as Optimized.
Click Finish and refresh the page. The new subdomain is configured and data routing status should show that it is Optimized.
The subdomain can be easily modified by clicking on Change and following the same procedure outlined above. A new CNAME record will need to be created.