Simple diagramm with 3 variables

Hi guys!

I actually have a pretty simple question.

How do I get a plot drawn with R as I have shown in the figure?

I have already tried with various codes (boxplot, etc..) but never get the right result.

Could someone help me?

Thanks in advance



To help us help you, could you please prepare a reproducible example (reprex) illustrating your issue? Please have a look at this guide, to see how to create one: