Demi Lovato will be filling in for Selena Gomez on Sept. 24, during the 2016 Global Citizen Festival on the Central Park Great Lawn. Lovato made the official announcement in a video message via Twitter on Wednesday.

“Excited to perform at #GCFestival in NYC 9/24! Take action to earn your free tickets: glblctzn.me/2bZ2R95," she tweeted.

Her announcement comes after Selena Gomez, a former headliner of the festival, was removed from the lineup. Gomez recently canceled the remainder of her Revival tour and told People in August that she'd be taking a break from the music industry to cope with side effects of her Lupus diagnosis. Gomez said she has been suffering from anxiety, panic attacks and depression, causing her to want to take the time to focus on her mental health.

The festival, headed into its fifth year, is a free event that aims to encourage world leaders to make changes on issues such as health, education, hunger and the environment. Lovato will be performing alongside headliners Rihanna and Metallica, and guest performers, Chris Martin of Coldplay, Ellie Goulding and Usher, to name a few. Chelsea Handler and Neil Patrick Harris are expected to host the event.

Fans can complete actions for the chance to earn free tickets to the event at globalcitizen.org. The event will also be streamed live on YouTube and MSNBC.