In the Challenge section, you can see any challenge invites along with upcoming, current and recent challenges that you are either a player or a watcher of.
Navigate to the section by selecting the Scoreboard icon at the top of the page and then selecting Challenges:
Once there, you will see any Challenge Requests you have along with any active challenges, completed, in sudden death or upcoming.
To accept or decline requests, choose “respond now”. A screen will pop-up with information on the request. You will be able to accept or decline in the bottom right corner.
To see the current scores on a challenge, click view details.
The challenge scores will be displayed depending on the type of challenge.