Almost all of my TTRPG friends are online as well! Unfortunately, there isn't a VTT for this. Given the game's simple setup and easy rules though, I find just doing an online voice chat works perfectly well. I use a private discord server with my friends where we can have a voice chat going, a text chat for logs and notes, and either Jamspace or Canva whiteboard to keep track of ongoing things for the session. I've even run it via play-by-post without any hassle. A VTT would be definitely be sweet, but I haven't found myself desperately needing one for this or other 24XX games. I hope you and your TTRPG buddies can give it a go!