Demographic Setting

After a few days of using this plugin, I saw a report on my analytics. But when I look for demographic report, there is a message looks like this:

Your Demographics and Interest Reports have been enabled, but your Analytics tracking code does not include the necessary support to show them. LEARN MORE about the simple, one-line, one-time change to your tracking code to add this support.

So I look on the “Learn More” there told that we have to add a code like this:

ga(‘require’, ‘displayfeatures’);

Where I have to input the code?

Thank You.

https://www.ads-software.com/plugins/woocommerce-google-analytics-integration/