[TYPO3-english] Rookie Q - How / where to add Optimizely snippet?

[Paul Stevens]

Hi Typo3 Community,

I am extremely new to Typo3 and I am having trouble with my Optimizely snippet.

Could someone point me to a how-to or walk me through how to add the snippet to the header?

I tried: Template > Homepage > Setup but I get an error in Optimizely that the snippet is not correctly implemented. 

Thank you.