If you prefer to manage the mbox.js file yourself and host it outside of dynamic tag management:
On a property’s Overview page in dynamic tag management, click Add a Tool.
From the Tool Type drop-down list, select Adobe Target.
In the Tool Name box, type “Adobe Target.”
From the Library Retrieval Method drop-down list, select Manual.
Click Create Tool.
Specify your Target Client Code on the resulting screen.
For information on how to obtain your client code, see Step 1: Add the Adobe Target Tool.
Expand the Library Management section of the page, then select the At URL option from the Code Hosted drop-down list within the Custom section.
Ensure that the Load Adobe Target Library Synchronously option is selected.
Specify the HTTP and HTTPS URLs.
Click Save Changes on the Adobe Target Tool page.