How to compress a certain part of an image?

Question

Unity

I have a button-picture, the corners are rounded, I need to reduce it in length, if you completely edit the length of the button, then it will be flattened, it is necessary that when changing the length, only the central part is adjusted, and the side parts are not deformed ...
Somewhere, once I went through this and I know that somehow it is possible, but I forgot how... tell me how?

Answer 1

On the sprite, mark the lines along which the demarcation will be. In the Image component, select the slice mode.