Martin Garrix played his first set in 2021 at Hydeout: The Prelude Digital Festival. You can watch his performance in virtual world called the The Sanctum started from 5 March 2021 and will be available to watch on-demand.
To have access to the performance, you need to make account in Hydeout World website and buy the coins. There are two payment options available for Hydeout: The Prelude. The full episodes available with a Season Pass for USD $49.90, or, users can register for a Pay-As-You-Go pass, and purchase a HydeCoin Lite (1,250 HydeCoins) for US $9.90. Martin Garrix performance is 950 coins. Playback will be available for five days after purchase.
Here are the trailers and some fan posted snippet from the performance.
Garrix Interview 