If you want to add an HTML 5 player to your account then you need to open the Player URL on the HTML 5 display.
The Player URL can be found in the administration view within the designer.
To find the player URL you have to click on the Administration button and navigate to the tab Licenses.
Click on the "Show player URL" button next to a HTML 5 license to view the player URL. This is the URL you need to enter on the display.