eg_data_x <- data.frame(
period = c("1", "2", "1 + 2"),
grp = c("1", "2", "1 + 2"),
sum_period = c(20000, 30000, 50000))
eg_data_x$period <- factor(eg_data_x$period, levels = c("1", "2", "1 + 2"))
eg_data_x$grp <- factor(eg_data_x$grp, levels = c("1", "2", "1 + 2"))

total_chickens_by_period <-  (
(ggplot(data = eg_data_x, aes(x=period, y=sum_period, fill = grp)) +
 geom_bar(stat = "identity", color = "black")) +
scale_fill_manual(values = c("red", "green", "gold")) +
scale_y_continuous(labels = scales::comma) +
geom_text(aes(label = sum_period), position = position_stack(vjust = 0.9), fontface = "bold") +
ggtitle("Total Rubber Chickens by Period") + xlab("Period") + ylab("Chickens") +
theme(plot.title = element_text(color = "black", size = 14, face = "bold", hjust = 0.5),
      axis.title.x = element_text(color = "black", size = 12, face = "bold"),
      axis.title.y = element_text(color = "black", size = 12, face = "bold")) +
labs(fill = "Period") )

total_chickens_by_period