casthely

I watch the tutorial videos. When I tried to do the editing with the brushes in terms of the blemish removal, impainting the are not working what is wrong? The tutorial looked quite simple however it is not working for me working on a JPEG

I am having the same issue Impainting brush, healing brush, blemish removal brush All not working? I watched the tutorials which are quite simple Not working.. help I am using JPEG from my Nikon camera