The start function will play the animation of your decision. You will need to follow and click on the dotted yellow action circle to move forward with the decision animation logic. An attachment will open if there is any in the animation process.
Navigate to the "Play" panel and click on the "Start" function to start the animation of your decision logic.
A new window will open where you will be able to interact with your animation; play, stop it and follow the logic of your decision by clicking on the dotted yellow action circle. On the left side, you will also see an animation trace to be able to follow the decisions which have been completed.