After the services are rendered, you can mark them as Completed and then proceed to take the payment from the guest.
Note: If the services are prepaid, or the payment for the services has been made in advance, then you can mark the services as Completed after you render the service and then close the invoice from the Point Of Sale (POS).
Learn more: Take Payment in Advance.
To mark the services to services as completed
Open the Admin Queue.
Go to the Services in Progress section.
Click Mark Completed if you have rendered the service.
The duration of the service is updated and the appointment block changes its color from white to grey.
Note: Till you click Checkout and collect the payment, the appointment block will be available in Services in Progress section.
Next Step: Checkout the Guest and take payment