Hello, your code is particularly useful as forum users will fail to be able to run it by virtue of not having your private objects. Data_m2 etc. See the reprex guide to overcome this.
In general though , the solution would be to annotate with a geom_text or geom_label depending on the required effect. see for example:
How to annotate a plot in ggplot2 – the R Graph Gallery (r-graph-gallery.com)