Failure in filler reinforcement
With this problem, the following problems are possible:
Water does not step into the barrel. First try to shake and twitch a plastic lever or wire, a float weighs on it. Perhaps your adjustment has simply been violated. Then turn off the water supply valve and unscrew the flexible hose, it connects the water supply to the tank. If there is water flow, then you do not have a hose, then you should change the eyeliner. If it’s not a hose, then clean the place where the tank and the pipe are connected. Then connect everything back. They ate and this did not help you, then change the float valve.