I live in an apartment and I want to fix my leaking faucet in the tub. How do I turn off the main water to the tub.

I live in an apartment and I want to fix my leaking faucet in the tub. How do I turn off the main water to the tub.
There are several ways. (1) you can turn off the water at your water service shut off valve, ( This shuts down the entire apartment). (2) Most tubs have a access panel behind the tub drain to give access to the drain assembly. In years gone by we installed wheel stops there so the valve could be serviced.
(3) In newer one handled valves the manufacture installed screw driver stops on the valve at the point where the supplies connect to the valve. To access them, you must remove the handle and the face plate. The screw driver stops will be on either side of the valve. Good luck, Tom