Open the game to the "Adventure Home" Screen. There will be a 3 line menu on the top left of the screen. You can tap on it to bring up all the menu items.

The first row of the menu items screen is your Account details, clicking it will open up to a window with your Player Name & Player/User ID, which is often denoted as UID.

You can press the copy button to copy the Player/User ID and paste it into a support form - this helps us locate your account quickly.