mistake in My Health Declaration

sai23

I am newbie here and i am hoping na matulungan nio ako.
so this is my situation. i am applying for 482 visa. i have a hypertension and i am taking a medication. ngaun, my agency created an immiaccount for me at hindi pala nila nailagay na i am taking medication. dumating yung medical referral ko at doon ko lang nalaman na naka NO lahat sa my health declaration. possible pa bang mabago un without causing delay sa visa processing ko.. BTW. nalodge na po visa ko.
and now my agency is asking a medical certificate that i am taking medication. hindi ko alam kung para saan.