The prize board is a section of the game where you can place cards from your collection to obtain prizes every certain period of time.
To access it, go to the in-game Store and then go to the Gems section, which can be found in the bar at the top of the screen.
To get the free prizes of your cards, you will have the possibility to place up to three cards at the same time. If you haven't placed any cards yet, you will see three empty spaces and, if you click on any of them, you will be redirected to a section with all your cards so that you can choose the one you want to place.
In case you already have a card selected and you want to replace it, you must click on it and select "Replace". At that time, you will also be redirected to a section with all your cards, so you can choose the one you want to place.
You can also select the cards to be added to the board from your Album. To do this, go to "Get more cards" > Album and, once you are there, select the card you want and press "Add". In case you already have your board full at that time, the game will ask you to select the card you want to replace.
You will be able to see the time remaining to obtain your prize in each card and, once it reaches zero, you will have to press on the card to claim your prize.
For more information about your Album, we invite you to visit the article: Where can I find my album?