To participate in Trade Battles, you must first build your Central Office. Choose one of the modes available to you. A window will open in which you can see the ranking of the best players and the reward you can win. You will need fuel to start the game. Refuel by pressing ‘+’ or wait for the fuel to restore over time on its own. Tap the ‘Fight!’ button to start the selection of participants. This might take a few moments, so be patient and don’t quit the game.