Google Optimize is now automatically displaying a custom page for users that arrive to a website via a Google Ads campaign, Google announced this month. According to Google, the custom page will be visible to the user for 24 hours.
To display a custom page, advertisers need to add the Google Ads rule to ensure the custom page is shown to people who first arrive from a Google Ads campaign. Advertisers are also able to use a custom page by using a UTM parameter (utm_campaign) on the urls of email, search or any other campaigns.
Google says the Google Ads and UTM parameter rules are already available to use in Optimize and in Optimize 360.