Percentage of each cluster in Seurat
pt &lt;- table(Idents(myobj), myobj$orig.ident)
pt &lt;- as.data.frame(pt)
pt$Var1 &lt;- as.character(pt$Var1)

ggplot(pt, aes(x = Var2, y = Freq, fill = Var1)) +
  theme_bw(base_size = 15) +
  geom_col(position = "fill", width = 0.5) +
  xlab("Sample") +
  ylab("Proportion") +
  scale_fill_manual(values = brewer.pal(12, "Paired")) +
  theme(legend.title = element_blank())


This shall work. myobj is your seurat object. This is my old code so if I remember correct, orig.ident is your treated and untreated conditions. Idents should give you cell clusters.
If this does not work, please let me know