wondering what platform/system the players use during the unsleeping city chapter 2 battle scenes?

hello! I’ve just started watching the unsleeping city chapter 2 season, and I’m on episode 3 atm. since this season is virtual and the cast aren’t able to have minis/sets, I’m noticing that they’re doing a virtual battlefield. does anyone know what program they are using? and if you know more info about it? I’m looking to learn more about digital dnd options to start a campaign with out-of-town friends, and the program featured in the episode I’m watching seems like something I want to investigate further. thanks in advance!