When one books a test one is asked for one’s Gender (options Male or Female only). When one requests to give feedback on the same website, for example to point out that for clarity it should be asking one’s Sex not Gender, one of the metadata that is requested is one’s Sex (with several options such as prefer not to say). I would have thought that for a disease like covid19 which clearly does know that sex is male or female, the website would be designed more carefully in order to collect quality data.