How can I retake my PECB Exam, as I failed the exam in first attempt? Do I need a new PECB Exam Coupon? Do I need to pay any fees?

The second attempt at PECB Exams is free. There is no need to have a new PECB exam coupon for a retake of the exam. The same coupon you have used for 1^st attempt on the exam is also good for the second attempt also.