It looks like stripped threads in the alloy crank arm.
If so the crank extractor wont fit.

You can get the cranks off by using a hammer and chisel. Put the bike upside down. get a cold chisel and a hammer. place the chisel tip at the place where the axle goes in the back of the crank. With the chisel quite flat on the bottom bracket of the frame. Maybe come off with a sharp tap.

This method, done with care, wont damage the cranks. In fact it can sometimes sort them. As cranks like those in the picture. alloy arms with steel chainrings. They have a spline form on the crank arm/ chainring joint. Then the alloy is peened down to hold the chainring in place. This sometimes wears and the ring can move.