When I try to take payment for an appointment in the Square appointments app, sometimes it will allow me to send them an invoice as the payment method, and other times it will not. When I am unable to, the option is greyed out. I have found that if the appointment was made on a computer or by a customer, I am unable to link an invoice to it and the option to charge them via invoice under 'review and checkout' is greyed out. However, if I make the appointment in the Appointments app on a mobile device, then the option to bill the appointment as an invoice is available. What is going on here? How can I make it so I can always take payment as an invoice?
