@Geeor, you should take care to avoid the shoulders being cut off before the edge of the canvas (below is another example, showing the gaps between where the shoulders are cut off and the edge of the canvas).

All you need to do is be sure you don't crop the source image too narrowly before putting it through remove.bg, so that you have enough shoulder width to work with. If the original source is cropped already, just use clone stamp to recreate the missing bits.