Agree with justinbrett. Services Australia say “take your Documents to a recognised vaccine provider “. Contact your Australian GP and see if they will be happy with the documents in their hand and you at the other end of the phone
Did they specifically mention 72 hours prior to arrival at the Hotel. I can’t image every Hotel requiring this? Maybe they meant arrival into Italy? Australia is a List D country
https://www.smh.com.au/national/a-million-reasons-to-get-jabbed-new-lottery-offers-prizes-for-vaccinated-people-20211003-p58wqk.html
For anyone interested in a bit of financial incentive
Not sure what you will be doing in Melbourne but I don’t think a transit permit is appropriate? You are only allowed to go to accomodation and buy food whilst “transiting“
https://7news.com.au/news/crime/two-charged-over-victoria-picnic-attack-c-4075088
Two people have been charged, I wonder if they handed themselves in or were “found” by Police?