Unable to Insert Google Remarketing code / tag on home page

I tried for many hours but was unable to insert remarketing code from google on home page. But was successful on other pages like http://www.guitarlessonsingapore.com.sg/coach-terence-choo/ for example.
I need to learn how to have the code active on main page http://www.guitarlessonsingapore.com.sg/

Thanks.

Terence