Overview
An API secret key helps to protect your data from unauthorized access. If you do not use the API secret key, anyone who knows your measurement ID can send event data to your GA4 property!
If you are using the Measurement Protocol to send event data to GA4, you should be using an API secret key (the Measurement Protocol is a way to send data to GA4 programmatically).
The Fullpath Way
By default, Fullpath sends conversion events into Google Analytics 4 using the gtag pixel (our code snippet sends conversion data directly to the customer's pixel, one pixel to another on the dealer website), which means you do not need to use the API secret key.
If you or your OEM Brand would like us to send conversion data into GA4 using a Measurement ID and Secret API key, we can set this up by request. Your Customer Success Manager will need both the Measurement ID and Secret API. Setup could take up to 3 business days.