When you create a live stream inside Brid and set everything up, go to your live streams list inside Brid and select your current live stream that you want to edit and use.
On this screen, you will see some basic stats and the PUSH AD section.
Under this section you will see the number of viewers your current stream has and also a dropdown where you can choose which ad tag URL you want to push to your users.
You also have an option in this dropdown to use a custom ad tag URL.
Once you select your ad, click on the PUSH button below and you are done!