NBN Installation has different Service Class types. Yours is under Service Class 3 which means that the service can be activated remotelly and the equipment is already installed called the NTD (Network Termination Device). The Service Class types are being determined by NBN Co and is relayed to NBN ISPs database.
I would recommend to ask the building admin of the whereabouts of the NBN NTD. This is oftentimes a common case with units/apartments.
The service has been activated.
You may check these articles for reference:
Let us know how it goes and if you were not able to locate the NBN NTD.