Paypal not working when booking appointments

When selecting an appointment I am presented with the confirmation page.

When I enter the details on the page and confirm the appointment nothing is happening.

I have taken Appointment + out of sandbox mode and entered my PayPal email address.

These are the three short codes I have on the page;

[app_service_providers]

[app_schedule]

[app_confirmation]

Can you please tell me what to do.

Thanks