If you are not able to save your photoshop’s image as PNG after cutting the required image that is very easy to solve the problem.
Solution to save photoshop image as png.
The common reason that you cannot save your photoshop image as png is image modee CMYK . Go to image option in your photoshop or press Alt+I there you will see option Mode go to that option and select RGB there then try to save your image as PNG and you can save your image as PNG.