I make resolution change by how brakyes does but when I did it lower resolutions can see little area not all area with low quality how do I fix it
In unity there is no one-button-click fix for this issue. There are severval ways to deal with it. If you are making somehing specifically for some resolutions, i would manually change the positions of gameobjects for each resolution. Or if you want it to work universally, try this script given in the video How to fit your Unity Game on Different Mobile Screen Sizes - YouTube