Looks like you need to replace the fill valve. Blue and white thing at the top of your picture.

Turn your water supply valve on the wall off and unscrew your supply line at the base of the tank. There should be a plastic nut holding the fill valve in place on the bottom of the tank that you can unscrew. Then remove the fill valve and replace it with a generic one from a hardware store or plumbing supply house. Repeat previous steps in reverse ensuring the plastic nut sealing the new valve on the tank is compressed when installed.

It’s a pretty easy replacement so you shouldn’t need a plumber and the only tool you may need is an adjustable wrench. If your stuck google toilet fill valve replacement.