plot_1 <- ggplot(table_2,
                   aes(x = Year, stratum = HC50, alluvium = HC50,
                       y = Normal,
                       fill = HC50, label = sprintf("%0.1f", round(Freq, digits = 1)))) +
  scale_fill_manual(values = mycols1) +
  scale_x_continuous(breaks = seq(2014, 2023, by = 1)) +
  geom_flow() +
  geom_stratum(alpha = .5) +
  geom_text(stat = 'stratum', size = 3.5)
plot_1

In geom2trace.default(dots[[1L]][[24L]], dots[[2L]][[1L]],  ... :
  geom_GeomFlow() has yet to be implemented in plotly.