[calc] IF ... how to access Bckgrnd, turn it Red?

HP Pavillion, win 10;
in =IF B2<>A2, [HOW TO GET IN CELL] .> [AND DISPLAY IN RED] ?

Thanks!

Which LibreOffice Version?

[HOW TO GET IN CELL]

Which cell?

Please read: LibreOffice CalcConditional Formatting Guide

Do you know the Style function?

https://help.libreoffice.org/6.4/en-US/text/scalc/01/04060109.html?DbPAR=CALC#bm_id3149425