Link Campaign Manager to Google Tag Manager
1. Copy your Google Tag Manager container ID from the top right corner of your container homepage.
2. Navigate to the Advertisers list on Campaign Manager 360, click on the advertiser you want to link to GTM, and click the Floodlight configuration tab.
3. Scroll down and expand the Google Tag Manager section, click on Link this Floodlight configuration to a Google Tag Manager container and paste your container ID in the appropriate field.
4. Click Save to send a link request to Google Tag Manager.
When you approve the association within GTM, the link status in Campaign Manager will change to Linked.