In Tron, bikes leave behind permanent trails on their path, and any bike that crashes into any of the trails or walls loses. You are Player 1, and you need to make every other bike crash, but since you control all bikes simultaneously, you'll need to figure out how to make the paths rotationally symmetric and still win.
Once you find the winning path, note down the binary numbers (in groups of 5) that each bike travels over. Order them by player number and then convert them to letters to extract the final answer.
Only one wall is not rotationally symmetric on the board, so the first bike that crashes needs to hit that wall. That means you have to travel across one of the three other squares that rotationally corresponds to the asymmetric wall. Once one bike crashes, it will create an additional asymmetry in their lack of continued path.
But if you go straight up at the start and make Player 3 crash, there will be no way to reach their side of the arena to use the new asymmetry without first passing through another bike's path. That means you'll have to go two one of the other two squares and make a different bike crash.
Notice that you can't go through the middle of the arena without crashing unless another bike has already crashed. Only one of the two other players that aren't Player 3 can be reached without going through the middle.
To make the other two bikes crash, you'll have to loop around back to the middle of the arena. Make sure you don't block your return path by turning too soon at the beginning!