Appointments plugin doesnt redirect to Paypal

Hello
I just installed the appointments + plugin for wordpress.
I have configured the service and provider and the settings of paypal in the backend.
however when i test in the frontend i can book the appointment but there is no rediection to the paypal.
when i click on confirm the appointment there is nothing that happens...
u can test it in this url http://toniribeiro.com/wptr/test-cal/
Thank You