Here is a start. How close to you want to get to the style of the plot you posted?
library(ggplot2)
DF <- data.frame(Conc = c("30", "80", "Combined"), Response = c(16, 18, 99))
ggplot(DF, aes(x = Conc, y = Response)) + geom_col(fill = "steelblue", width = 0.5) +
labs(x = "Drug Concentration", y = "Drug Response") +
coord_flip()

Created on 2020-09-22 by the reprex package (v0.3.0)