Using Tickformat

Mix.install([
  {:plotly_ex, "~> 0.3"},
  {:kino, "~> 0.18"}
])

Section

tickformat uses D3 number or time format strings. Use "%" to display values as percentages (a value of 0.5 renders as "50%").

alias Plotly.{Figure, Scatter}

Figure.new()
|> Figure.add_trace(
  Scatter.new(
    x: Enum.to_list(1..10),
    y: [0.1, 0.24, 0.18, 0.35, 0.29, 0.41, 0.38, 0.52, 0.47, 0.6],
    mode: "lines+markers"
  )
)
|> Figure.update_layout(
  title: "Y-Axis as Percentage",
  yaxis: %{tickformat: "%"}
)
|> Plotly.show()