The issue here is that the user wanted know how to add a script to the header of their website.
Solution:
This is possible to do with Toolset, however you will need to wrap the script tag in one of the WordPress hooks that allow you to insert the script into the header.
You can use the hook below.
[php]
function wpb_hook_javascript() {
?>
This can be added to the Toolset Custom code settings in Toolset -> Settings -> Custom Code, ensure that it is activated once you've set it up. If you want to have the code run only on the frontend then you will need to check only the frontend option.