To get your tracking page on all pages, you can add the code as an embed on all the master layouts. Though this does not add the code to the head of the page, it will work as expected.
  1. Go to onMessage
  2. Select Website > Main Site
  3. Select Master Layouts
  4. Click on a layout
  5. Drag an embed widget onto the page
  6. Click the Settings cog wheel
  7. Paste in the code
  8. Click Save