The information below is from their FAQ on their website
Q. Is it possible to re-apply? A: It is not possible to create an additional application on our website, but you are able to update your ONE online application. If your application has previously been unsuccessful but you would like to re-apply to the program, you should continue to update your one online application. All changes & updates made to your online application are registered by our systems and reviewed at an appropriate time. If the airline decides to review your re-application in the future, you would be contacted accordingly at that time - but it is not possible to provide information as to when or if this may happen