（服务）功能按下按钮不起作用

I seem to be having an issues using a service. I created a controller file and added a service above it. I injected the service into the controller and am trying to access one of the service's functions. I am calling the function using a button. The problem is when I press the button nothing happens. I have tried testing the result by outputting to the console but nothing is working.I seem to be having an issues using a service.