If you would like to apply 3rd party pixels on a placement level, leave the 'Include Creative Variant’ box unchecked. However if you would like to track on a creative variant level, tick the box so trackers will be applied to all creative variations. The following steps will apply to either strategy.
Click Download Template.
Open the file and paste any 3rd party trackers in the impression pixel column, Js column, click URL and click tag. Save the sheet.
Click upload trackers and select the file that you saved above. Upload this into the platform and click Save.