Adapt the hue of the background or vice-versa so that it looks harmonious

I have that app called PhotoRoom, it makes it easy to insert an image with a created background, it even adapt the hue of the background or vice-versa so that it looks harmonious. I don't find it easy to insert any photos with my created background. The ration is not sensed by the program the hues and light neither... if it is possible to accomplish that can you do a demo.?