How to combine Boxplot and Grubbs test to plot figure?

Question

If I wish to label outliers in the boxplot and use Grubbs' test for outlier detection, I can use Grubbs' test while doing data preprocessing and then label the outliers on the boxplot. How could I improve my codes?

Here is my origimal data:

SFP2<-structure(list(Pos_heliaphen = c("Y07", "Y16", "Y36", "Y45", 
                                 "Z06", "Z23", "Z36", "Z45"), traitement = c("WS", "WS", "WS", 
                                                                             "WS", "WS", "WS", "WS", "WS"), Variete = c("SPE", "SPE", "SPE", 
                                                                                                                        "SPE", "SPE", "SPE", "SPE", "SPE"), Date_obs = structure(c(1685318400, 
                                                                                                                                                                                   1685318400, 1685318400, 1685318400, 1685318400, 1685318400, 1685318400, 
                                                                                                                                                                                   1685318400), tzone = "UTC", class = c("POSIXct", "POSIXt")), 
               SF_Plante_Totale = c(103461.423, 107125.5471, 87559.8568, 
                                    108760.509, 95280.1512, 117435.0697, 129047.8228, 106354.3793
               )), row.names = c(NA, -8L), class = c("tbl_df", "tbl", "data.frame"
               ))

Here is the code I tried:

library(ggplot2)
library(outliers)

test_result <- grubbs.test(SFP2$SF_Plante_Totale, type = 10, two.sided = TRUE)

print(test_result)

p <- ggplot(SFP2, aes(x = Pos_heliaphen, y = SF_Plante_Totale)) +
  geom_boxplot() +
  labs(title = "Boxplot with Grubbs' Test Outlier Detection")

if (test_result$p.value < 0.05) {
  p <- p + geom_point(aes(x = Pos_heliaphen, y = test_result$alternative * test_result$statistic),
                      color = "red", size = 3) +
    geom_text(aes(x = Pos_heliaphen, y = test_result$alternative * test_result$statistic),
              label = "Outlier", color = "red", vjust = 1.5)
}

print(p)

Here is the figure I got:

How can I have the right boxplot with outliers analysed by Grubbs test to be presented in the figure?