How do I restore the 4 light blue icons on my home screen?

[Android Central Question]

I have an LG Grace Android phone. There are four "stock original" shortcut icons on the home screen. One is "Battery Saver", one is "Memory", one is "Storage", and the fourth one I can't remember what it's called because I accidentally deleted it. How do I get that fourth icon back on my home screen? All 4 icons are light bluish green in color.