Manually adding the labels in ggplot2

Question

I have data as follows:

df <- structure(list(value = c(0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 
0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 
1,