Note: To add Google Analytics, Adwords, or Facebook Pixel, you must first set up those accounts.
For information on how Google Analytics works, this article may help:
Collect campaign data with custom URLs – Analytics Help
STEP 1: Click ‘Edit’ in the sidebar menu of your campaign.
STEP 2: Click ‘Marketing’ in the new sidebar menu.
STEP 3: Insert your Google Analytics, Adwords, and/or Facebook Pixel account numbers in the field(s).
STEP 5: SAVE!
Can’t forget that guy!