On a general basis a fit to fly letter is a medical certificate written by a doctor that confirms your fitness to fly. It is a way to verify if you can travel safely by having a doctor reviewing your symptoms, medical history, and medical examination if necessary. You can follow the below pathway on the app to proceed further with requesting a fit-to-fly letter:
Online Consultation>Administrative Help>Request a Letter/Report>Fitness to fly letter
Please provide as much of details as possible and proceed as required.