If your toilet is leaking about the handle, then it is clear that your water level in the tank is far too high.
If the water level is set properly at the manufacturer's suggested height (see the water level mark on the inside of the tank...backside) it should be nowhere near high enough to leak thru the handle opening.
You adjust water level height by sliding the float up or down by the clevis on a Fluidmaster, adjusting the set screw or by bending the rod down if necessary on a ball-cock , or by turning set screws on fill valves.
If the water level is already below handle level and you still have a leak, check the tank for a crack under the handle hole.
PS. If you need to remove the handle, remember the
nut holding the handle in place from the inside is reverse threaded.