r-plotly Filter Button to Display All Data

I am attempting to use r-plotly to make an interactive graph. I would like there to be a button to filter by groups specified in the data. In the example below, the button works to filter the data into group 1 and group 2, but the button for "All groups" does not display all of the data. Anyone have suggestions?

df <- tibble(x = c(1, 4, 2, 7), y = c(3, 1, 8, 4), group = c(2, 1, 1, 2))

fig <- plot_ly(data = df, type = "scatter", mode = "markers") %>%
  add_trace(type = "scatter", mode = "markers", x=~x, y=~y,
            transforms = list(
              list(
                type = "filter",
                target = ~group,
                operation = 'in',
                value = unique(df$group)
              )
            )
  ) %>%
  layout(
    updatemenus = list(
      list(
        type = 'dropdown',
        active = 0,
        buttons = list(
          list(method = "restyle",
               args = list("transforms[0].value", unique(df$group)[2]),
               label = "Group 1"),
          list(method = "restyle",
               args = list("transforms[0].value", unique(df$group)[1]),
               label = "Group 2"),
          list(method = "restyle",
               args = list("transforms[0].value", unique(df$group)),
               label = "All groups")
        )
      )
    )
  )
fig