Google's new Remarketing Tag helps you to easily create remarketing lists by allowing you to place one tag across all pages on your site.
To connect your website to Google Remarking Tag:
Go to ads.google.com and Sign In, or create an account with Google Ads.
Once you sign in, click Tool & Settings and select Conversions.
Click the plus button.
Fill in your conversion details and click Next.
Select Add the tag to your website code.
Copy the Application ID code snippet from the code section, as shown in the screenshot, and click Next.
Click DONE to submit the new conversion.
Go to your Website Editor, click Settings, and select Plugins from the drop-down list. Click Manage, then Add New Plugin and add Google Remarketing Tag.
In the Application ID field, enter the code snippet you copied from Google Remarketing Tag. Insert the code, Enable it, and click Save.
Publish your website to update it with the changes you've made.