Create conditional formatting in a second cell when ticking box in first cell.

Hello! I'm very very new to using Numbers, so forgive me if it's a silly question. However, I didn't find anything through my search other than a very convoluted video that wasn't exactly my question. Basically, I have this simple cell that tells the salary and a checkbox near it, for when it's paid. I'd like, if possible, for the "salary" cell to be highlighted when the box is ticked. I'll leave a picture of it for reference (in the picture it's coloured for unrelated reasons, I had just forgotten to remove the formatting from another cell when I took the screenshot).

Any tips/info on this is appreciated, thank you!

Iane.