@tab0ret, not bad but before , have a look at this thread for the guidelines related to what cuts should look like and various video tutorials on how these guidelines can be achieved. All cuts are to include a collar, the chin should be no more than 2-3 pixels above the bottom of the canvas and the edges should be smooth and not jagged. Images should also be in 250x250, or 180x180 if the source image is small and/or poor.

Whatever method you were using resulted in a black square beneath the hair, so it's not ideal.

I recommend using remove.bg and photopea.com (which is basically a free online equivalent to Photoshop), using the techniques outlined in this video:

@tab0ret also,in addition on @mons words ,in the case like this (when the original source is pre-cut) there's need for additional cleaning up.