Medical examination for 189 visa

Australia
#1

Hi all, when filling up the 189 visa application, i don’t see any information about medical examination. Does DHA request to get medical exams done after lodging the application? if so, how long do we get to finish them?

I am aware that we may be to able to generate the HAP ID before lodging the application. Is there any advantage to do this rather than waiting for DHA to request medicals?

#2
#3

Thanks for the response. After paying the visa fee, is it possible to link the existing HAP ID to the visa application?