USING META BOX
In addition to the manager you have a Meta box in single page and single post WordPress editor.
This Meta box is useful when you need to put a tracking code while you are creating a page or a post.
Is also useful when you want to exclude a certain page from being tracked.
To do that find the Meta box in the single post editor, as shown below.
The Meta boxes can be deactivated in the settings if them are annoying you.