Adsense Ads Also Need Script in Header?

Hi,

In the documentation on the settings page of the adinserter site it says that the following needs to be added to the header:

<script async custom-element=”amp-ad” src=”https://cdn.ampproject.org/v0/amp-ad-0.1.js”></script&gt;

Am I correct in assuming:

1. I go to Settings (gear) –> Header and paste it in here?

Also, I note that I can choose server side detection to only insert into header when it is on a specific form factor (e.g. mobile). But can one select only one option?

For example, say right now I want to add the above script to the header and so I select to have this only happen on mobile.

Now lets say that I have an other script I need to add another script that I would only want to appear on desktops. Is there a way for me to do so? Or do I have to choose either to have the insert for mobile or for desktop?

Thanks!

The page I need help with: [log in to see the link]