If you are an independent contractor to a brothel, you are making what is supposed to be a free and equal agreement with a brothel operator that is good for both of you.
You have the right to negotiate the contract to include things that are important to you. You also have the right to keep a copy of the written contract.
In reality, often the brothel operator has, or seems to have, more power than the sex worker. If you want to even up the balance, you can get legal advice on the contract you are being asked to sign from:
the New Zealand Prostitutes Collective (NZPC)
a Community Law Centre
a lawyer.
It’s common for brothel operators to include in contracts a system of fines for things like turning up late or wearing the wrong clothes. If these fines are unreasonable and more like a punishment than about the true cost to the business of what you’re doing, then your boss might not be able to get them enforced if you took your boss to court. Someone from the Prostitutes Collective can help you negotiate a better contract.