To embed a snippet on your page you can use the embed element. To use this please go to the desired place on your page where you want the embed element to show up and click on the plus.
You can now add the embed element, and will see the following on your page:
By clicking on the embed icon you can embed your own code:
By clicking on the arrows icon you can also edit the size for both mobile and desktop versions.
Please note that it will only be visible on the published campaign. If your embedded piece is not visible please check to see if you have copied the right code first.