WordPress WooCommerce job: ClickSend and Bookingwp -- 2

I have a "bookingwp" plugin that allows customers to book appointments at selected times and dates. I have "clicksend" installed which sends out SMSs based on Order status like "Processing" "Completed" etc. I need to send out an SMS 3 hrs before the appointment date chosen by the customer. Basically Automating the task, Just like how it sends out an SMS when someone creates a new appointment. Let me know if you have any questions. Bid with the word "Clicksend" so I know you read the whole description. Please only reply if you are 100% sure you can do it. I need it done in less than 3 days.