To charge your client's credit card after the appointment, go to "My Practice" and choose "Appointments" from the drop down menu.
Click on the appointment for which you want to charge your client. (Please note that you must have selected the option "I'll charge client's credit card" or “Send payment link to the client” while creating the appointment).
Click on the "Receive Payment" button and a new window will open. Click on “Collect Payment” to receive the payment from your client.