The cashflow loan through IRD that Zoe mentions above is available on this link https://www.ird.govt.nz/covid-19/business-and-organisations/small-business-cash-flow-loan
Have you spoken with your landlord about coming to arrangement that is acceptable to you both during this time? Also have a look at your lease agreement and see whether there is a clause in there that talks about what happens if you are unable to access the premises (as under Level 3 & 4). Some lease agreements have a clause that essentially says if you can’t enter the premises then the landlord and tenant must come to a mutually acceptable arrangement around the payment of rent.
Andy also asks some great questions that would be worth putting to your landlord so taht they understand your situation fully. For the landlord getting a new tenant during this time may also be very difficult for them so it’s in their interests too to come to an arrangement with you.
Best of luck.